An electric working machine comprises a motor, a switch, a drive device, a brake device, and a failure determiner. The switch is configured for operation by a user, has an on-state and an off-state. The drive device is configured to drive the motor in response to the switch being placed in the on-state. The brake device is configured to control deceleration of the motor to a stopped state in response to the switch being placed in the off-state. The failure determiner is configured to monitor deceleration of the motor during controlled deceleration and to determine whether the brake device has failed based on the monitored deceleration.