Power conversion circuit unit defined by rotation shaft-side line facing toward rotation shaft of electric motor, control output terminal-side line facing toward coil input terminals of electric motor and side lines connecting both end portions of rotation shaft-side line and control output terminal-side line is packaged with synthetic resin. Three-phase control output terminals connected to the coil input terminals are formed at control output terminal-side line. Power switching elements forming upper and lower arms for each phase are arranged in a zigzag formation along control output terminal-side line with power switching elements being offset from a substantially middle between rotation shaft-side line and control output terminal-side line toward control output terminal-side line. With this, size of power conversion circuit unit can be reduced, and heat of power conversion circuit unit can be efficiently released to the outside.