In the present invention, the clutch operation lever is changed from the clutch-off operation state at the start of the operation to both the clutch-on operation state, and a clutch operation And it is an object of the present invention to provide an operating structure of a lever.And a detent mechanism 25 for holding the clutch operation lever 20 and an operation from the clutch off operation position OFF of the clutch operation lever 20 to the both clutch ON operation positions ON2, When the clutch operation lever 20 is positioned at the thresh-up clutch ON operation position ON1 during at least one of the opposite operations, the engaging portion 32 of the detent mechanism 20 is engaged with the engaged portion 31 (Not shown).Further, a problem to be solved by the present invention is to provide a combine capable of setting the engine rotation to the rated rotation speed while setting the engine rotation to the ON state with the start of the harvesting work,When the work clutch lever 345 is operated from the off position (OFF) to the harvesting work position ON, the clutch control means 387 sets the descending clutch Ce and the cut-off clutch Cd to the ON state , The engine rotation control means 388 sets the engine rotation to the rated rotation speed regardless of the setting position of the accelerator setting dial 347. [ Thereafter, when the accelerator setting dial 347 is operated, the engine rotation control means 388 controls the engine rotation so that the rotation speed is set to the accelerator setting dial 347. [Further, a problem to be solved by the present invention is to constitute a combine capable of positively performing the on-off operation of the cut-off clutch at the start of the harvesting operation and also performing on-operation of only the descending clutch as necessary.The work clutch lever 345 is configured so as to be operable in an off position (OFF), a threshing operation position M and a harvesting operation position ON, and a thres
