In a walk behind mower (10) including a clutch (23) provided in a power transmission path between an electric motor (35) and driven wheels (13), a clutch actuating mechanism (24) interposed between the electric motor and the clutch for selectively engaging the clutch, and a control unit (140) for selectively supplying electric power from a power source to the electric motor according to a command from an operation switch (30), the clutch actuating mechanism includes a cam mechanism for engaging the clutch by using a force transmitted to an input end (23a) of the clutch in the power transmission path when the electric motor is being driven in a normal rotational direction, and the control unit is configured to drive the electric motor in a reverse rotational direction for a prescribed period of time before stopping supplying electric power to the electric motor when a command to stop supplying electric power to the electric motor is received from the operation switch.