A composite molded article contains a metal molded article and a resin molded article, which are bonded to each other, in which the metal molded article has a roughened bonding surface, a surface layer portion of the metal molded article including the roughened bonding surface has: open holes containing: a stem hole that is formed in a thickness direction and has an opening on the side of the bonding surface, and a branch hole that is formed from an inner wall of the stem hole in a different direction from the stem hole, and the composite molded article is bonded in such a state that the resin permeates into the open holes formed on the bonding surface of the metal molded article.