In order to achieve both a more compact device overall and reduced product costs, the present invention pertains to a drive device (1) comprising an AC rotary electric machine (PM), an inverter (40), and a case (2). The inverter (40) is fixed to the case (2) and the case (2) and the inverter (40) are arranged in a drive force source chamber (Q). The inverter (40) comprises a shunt resistance that detects current that flows to a switching element unit for each phase.