PROBLEM TO BE SOLVED: To provide a substrate assembled structure which contains a large-current substrate as a heating body and another substrate having a part having low heat resistance mounted thereof and in which the thickness of the whole substrate can be reduced with avoiding a thermal effect on the part having low heat resistance.SOLUTION: An assembled structure has a large-current substrate and another substrate having an electrolytic capacitor having low heat resistance which are assembled so that the mount faces of the substrates face each other across a predetermined space. The other substrate has the electrolytic capacitor mounted on the mount surface facing the large-current substrate, and a predetermined area containing a projection area of the large-current substrate on which the electrolytic capacitor is projected is a low heating area having a low heating value than an area around the predetermined area in the large-current substrate.