A hybrid drive unit includes a main body case having a connection portion connected to an engine, the main body case accommodating therein a rotating electric machine; and an inverter case integrated with the main body case, the inverter case accommodating therein an inverter that controls the rotating electric machine, wherein an inverter breather is disposed in a side wall portion of the inverter case on a side of the connection portion so as to provide communication between an inside and an outside of the inverter case.