The invention provides an electric apparatus having a printed circuit board with an improved heat dissipation capacity, and, in particular, to provide an electric apparatus requiring plural printed circuit boards that has an improved heat dissipation efficiency and can be produced at a low cost.A main printed circuit board 10 and a sub board 17 are composite-molded, and the sub board 17 is formed at an area close to or immediately below a heat-generating electronic component 23 or a heat dissipation plate 23a. Thus, by separating the sub board 17 off the main printed circuit board 10, a hole serving as a ventilating hole is formed in the main printed circuit board 10 at the area close to or immediately below the heat-generating electronic component 23 or the heat dissipation plate 23a.