Provided are a circuit assembly in which it is possible to eliminate or reduce a level difference between a mounting surface of a substrate and portions to which terminals that are electrically connected to a conductive member are connected, and that can be easily produced, and a method for manufacturing the same. A circuit assembly includes a substrate provided with openings and an electronic component mounted on one side of the substrate, a conductive member that is a plate-shaped member fixed to another side of the substrate, the conductive member constituting a conductive path, and a relay member that is fixed to a surface on the substrate side of the conductive member and made of an electrically conductive material, the relay member being accommodated in the openings formed in the substrate, at least one terminal of the electronic component being connected to the relay member.