diff --git a/CHANGELOG b/CHANGELOG
index c8661eec5..f284852ec 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -22,6 +22,7 @@ Core:
 - Moved custom slides to own app "topics". Renamed it to "Topic".
 - Added support for multiple projectors.
 - Added an overlay for the current list of speakers.
+- Added button to clear the chatbox.
 
 Motions:
 - Added origin field.
diff --git a/openslides/core/static/js/core/site.js b/openslides/core/static/js/core/site.js
index c66b9ed41..42a0fa044 100644
--- a/openslides/core/static/js/core/site.js
+++ b/openslides/core/static/js/core/site.js
@@ -1298,7 +1298,7 @@ angular.module('OpenSlidesApp.core.site', [
         });
 
         $scope.clearChatHistory = function () {
-            console.log("Clear");
+            $http.post('/rest/core/chatmessage/clear/');
         };
     }
 ])
diff --git a/openslides/core/views.py b/openslides/core/views.py
index 9982c5652..cdb95d40f 100644
--- a/openslides/core/views.py
+++ b/openslides/core/views.py
@@ -15,25 +15,27 @@ from django.core.urlresolvers import get_resolver
 from django.db.models import F
 from django.http import Http404, HttpResponse
 from django.utils.timezone import now
+from django.utils.translation import ugettext as _
 
-from openslides import __version__ as version
-from openslides.utils import views as utils_views
-from openslides.utils.collection import Collection, CollectionElement
-from openslides.utils.plugins import (
+from .. import __version__ as version
+from ..utils import views as utils_views
+from ..utils.autoupdate import inform_deleted_data
+from ..utils.collection import Collection, CollectionElement
+from ..utils.plugins import (
     get_plugin_description,
     get_plugin_verbose_name,
     get_plugin_version,
 )
-from openslides.utils.rest_api import (
+from ..utils.rest_api import (
     ModelViewSet,
     Response,
     SimpleMetadata,
     ValidationError,
     ViewSet,
     detail_route,
+    list_route,
 )
-from openslides.utils.search import search
-
+from ..utils.search import search
 from .access_permissions import (
     ChatMessageAccessPermissions,
     ConfigAccessPermissions,
@@ -667,13 +669,18 @@ class ChatMessageViewSet(ModelViewSet):
         """
         if self.action in ('list', 'retrieve'):
             result = self.get_access_permissions().check_permissions(self.request.user)
-        else:
+        elif self.action in ('metadata', 'create'):
             # We do not want anonymous users to use the chat even the anonymous
             # group has the permission core.can_use_chat.
             result = (
-                self.action in ('metadata', 'create') and
                 self.request.user.is_authenticated() and
                 self.request.user.has_perm('core.can_use_chat'))
+        elif self.action == 'clear':
+            result = (
+                self.request.user.has_perm('core.can_use_chat') and
+                self.request.user.has_perm('core.can_manage_chat'))
+        else:
+            result = False
         return result
 
     def perform_create(self, serializer):
@@ -683,6 +690,22 @@ class ChatMessageViewSet(ModelViewSet):
         """
         serializer.save(user=self.request.user)
 
+    @list_route(methods=['post'])
+    def clear(self, request):
+        """
+        Deletes all chat messages.
+        """
+        # Collect all chat messages with their collection_string and id
+        chatmessages = ChatMessage.objects.all()
+        args = []
+        for chatmessage in chatmessages:
+            args.append(chatmessage.get_collection_string())
+            args.append(chatmessage.pk)
+        chatmessages.delete()
+        # Trigger autoupdate and setup response.
+        inform_deleted_data(*args)
+        return Response({'detail': _('All chat messages deleted successfully.')})
+
 
 # Special API views
 
diff --git a/tests/integration/core/test_viewset.py b/tests/integration/core/test_viewset.py
index c1a803fa6..90b733ed5 100644
--- a/tests/integration/core/test_viewset.py
+++ b/tests/integration/core/test_viewset.py
@@ -1,4 +1,5 @@
 from django.core.urlresolvers import reverse
+from rest_framework import status
 from rest_framework.test import APIClient
 
 from openslides.core.config import config
@@ -145,3 +146,18 @@ class TestConfigDBQueries(TestCase):
         """
         with self.assertNumQueries(60):
             self.client.get(reverse('config-list'))
+
+
+class ChatMessageViewSet(TestCase):
+    """
+    Tests requests to deal with chat messages.
+    """
+    def setUp(self):
+        admin = User.objects.get(pk=1)
+        self.client.force_login(admin)
+        ChatMessage.objects.create(message='test_message_peechiel8IeZoohaem9e', user=admin)
+
+    def test_clear_chat(self):
+        response = self.client.post(reverse('chatmessage-clear'))
+        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        self.assertEqual(ChatMessage.objects.all().count(), 0)