An object of the present invention is to provide a polishing composition which can make the removal rate of a metal material and the removal rate of a resin material the same or close to each other in a chemical mechanical polishing process, which can accordingly avoid or suppress the occurrence of a step difference. The polishing composition contains: abrasive grains containing silica, with at least a part of hydrogen atoms constituting a silanol group located on a surface of the silica being substituted with a cation of at least one metal atom M selected from the group consisting of aluminum, chromium, titanium, zirconium, iron, zinc, tin, scandium, and gallium; and a dispersing medium. The pH of the polishing composition is more than 2 and 7 or less.