Abstract: A heat-generating component (3) is mounted on a surface (4b), on a case (12) side, of a circuit board (4). A recessed portion (5) is formed in a position facing the heat-generating component (3), on an inner wall surface (12e) side of a bottom wall (12a) of the case (12). Between an inner wall surface (5a) of this recessed portion (5) and the heat-generating component (3), a predetermined-sized component clearance (Ca) is provided, and a heat radiation member (6) is interposed in a position of the component clearance (Ca). A peripheral clearance (Cb) is provided between the surface (4b), on the case (12) side, of the circuit board (4) and the inner wall surface (12e) of the bottom wall (12a) of the case (12) on a peripheral edge side of the recessed portion (5).