To operate each operating tool with an operating force that is suitable to each operating tool with respect to the operation device that operates the opening and closing of a valve with the operation of an operating tool of either an operation pedal or an operation lever.

This device consists of an inner push rod 9 that vertically moves based on the operations of a progressing operation pedal 5L and retreating operation pedal 6L, an outer push rod 10 which vertically moves based on the operations of an operation lever 4L, a mobile body 11 that moves based on each different movement of the rods, a spool 12 that opens and closes a valve based on the movement of the body 11 and 1st and 2nd hitting machines 15 and 13 which engage the rods 9 and 10 respectively which give operation forces to the pedals 5L and 6L and the lever 4L respectively.