Abstract: (1) Various gear states are selected by movement of a shift lever 2 in a longitudinal shift path 13 and the gear stage is automatically shifted from starting to the maximum gear stage in an automatic speed change position D, so that an operator can run a vehicle with increased safety and easy operation without operation of the shift lever 2. (2) When a push button switch 3 provided in the shift lever 1 is pressed during the automatic speed change running, the gear stage during the running is fixed, so that inadvertent automatic shift is prevented and an optimum speed stage is maintained when the work load on the vehicle's engine changes, for example when the vehicle encounters a slope or a change in load during in operation. (3) When the gear stage is fixed in the automatic speed change position D and the shift lever 2 is transversely moved in the transverse shift path 14, the operator can vary the stages while varying one stage a time with the operator's will.