PROBLEM TO BE SOLVED: To provide a technology capable of suppressing temperature rise by a linear regulator function.SOLUTION: A semiconductor module 11 includes: a voltage generation section 15; and a heat dissipation mechanism consist of an isolating heat dissipation sheet 16 and a heat sink 17. The voltage generation section 15 can generate power voltage for driving a step-up converter 59 from voltage boosted by the step-up converter 59, by using a built-in linear regulator function. The voltage generation section 15 is installed on the heat dissipation mechanism.SELECTED DRAWING: Figure 1