A riding type mower includes: a vehicle body, a driver's seat mounted on the vehicle body; an operation part arranged around the driver's seat; a mower unit provided on the vehicle body; a shutter for closing a discharge port; a shutter moving mechanism for moving the shutter between a close position closing the discharge port and an open position opening the discharge port; and a lock mechanism for locking the shutter at the close position. The mower unit includes: a mower deck; a cutting blade installed inside the mower deck; the discharge port formed in the mower deck, through which mown grass cut by the blade is discharge from the mower unit to outside. A shutter operating tool for remotely operating the shutter moving mechanism to open and close the shutter is provided in the operation part. The lock mechanism is remotely operable from the operation part.