diff --git a/CHANGES b/CHANGES
index 95b7b5109bc..9c60620eb06 100644
--- a/CHANGES
+++ b/CHANGES
@@ -30,6 +30,7 @@ Bugs fixed
   different with one from ``index`` directive with "builtin" type
 * #7301: capital characters are not allowed for node_id
 * #7301: epub: duplicated node_ids are generated
+* #6564: html: a width of table was ignored on HTML builder
 
 Testing
 --------
diff --git a/sphinx/writers/html5.py b/sphinx/writers/html5.py
index f94dd60a390..80cedd3bdd8 100644
--- a/sphinx/writers/html5.py
+++ b/sphinx/writers/html5.py
@@ -734,11 +734,14 @@ def visit_table(self, node: Element) -> None:
 
         self._table_row_index = 0
 
+        atts = {}
         classes = [cls.strip(' \t\n') for cls in self.settings.table_style.split(',')]
         classes.insert(0, "docutils")  # compat
         if 'align' in node:
             classes.append('align-%s' % node['align'])
-        tag = self.starttag(node, 'table', CLASS=' '.join(classes))
+        if 'width' in node:
+            atts['style'] = 'width: %s' % node['width']
+        tag = self.starttag(node, 'table', CLASS=' '.join(classes), **atts)
         self.body.append(tag)
 
     def visit_row(self, node: Element) -> None: