Parking lock mechanism and working vehicle

A parking lock mechanism (25) used when a working vehicle is parked, comprising: a step part for locking (26), which is disposed adjacent to a brake step surface part (24) of a brake pedal mechanism (23); and a lock unit which is connected to the step part for locking (26) and which locks the brake pedal mechanism (23) at a braking position thereof by the step part for locking (26) being stepped.