PROBLEM TO BE SOLVED: To solve such defectiveness that a restraining mechanism having insufficient rigidity and getting caught by a wire in the forward/reverse changeover of a steering wheel in a controller provided with a conventional mechanism for restraining reverse travel. SOLUTION: In a controller provided with a mechanism for restraining reverse travel during work a PTO fork shaft 101 is horizontally extended at a transmission case, and a PTO clutch 41 can be put on/off by the sliding of the PTO fork shaft 101. A restraining member is provided on one end side of the PTO fork shaft 101, and an opening part of a main shift lever is disposed on one side of the transmission case 3. The restraining member is extended into the reverse position of a main shift lever rotating base part.
