A connector device includes: a motor-side connector 30 including motor-side terminals 31; an inverter-side connector 60 including inverter-side terminals 70; a motor case 10 including the motor-side connector 30; and an inverter case 50 including the inverter-side connector 60. The connectors 30, 60 are fitted to each other when the inverter case 50 is stacked on and coupled with the motor case 10. The motor-side connector 30 is fixedly mounted in the motor case 10 via a mounting hole 11 of the motor case 10. The inverter-side connector 60 is supported on the inverter case 50 while penetrating through a mounting hole 79 of the inverter case 50 in a radially freely movable manner.