To provide a vehicular ac motor which prevents an output terminal from being directly covered with water.

The vehicular ac motor 100 includes a frame 1 which supports a rotor 3 and a stator 2, a rectifying device 4 which rectifies output current from the stator 2 and has the output terminal 43, and a rear cover 5 which covers electronic components including the rectifying device 4. The rear cover 5 has drain windows 53 formed on the side of the output terminal 43 and walls 54 formed closer to the output terminal 43 and adjacent to the drain windows 53.