CIRCUIT ASSEMBLY

Disclosed is a circuit assembly having a novel structure that enables circuit components to be laid out in a lower case with high design flexibility and higher spatial efficiency. A circuit assembly includes: a lower case for accommodating lower circuit components; an upper case for covering the lower case; upper circuit components attached to the upper case, and a fastening member holder for holding a fastening member for fixing the upper circuit components to the upper case, the fastening member holder being provided in the upper case.