A power door device includes: a motor actuator to open/close a vehicle door; a controller to control driving of the motor actuator and include an abnormal state dealing unit; an information unit to acquire information about a vertical vehicle acceleration, and a motor load for the motor actuator; and a diagnostic unit to generate an abnormal signal when the motor load exceeds a predetermined load threshold and when the vertical acceleration does not exceed an predetermined acceleration threshold. When the motor load exceeds the load threshold and the vertical vehicle acceleration does not exceed a predetermined acceleration threshold, the diagnostic unit diagnoses an abnormality generates the abnormal signal. The abnormal state dealing unit performs the abnormal dealing control including stop movement during the door opening/closing in response to the abnormal signal.