To provide a tractor for working that can be intuitively set its running speed after automatic deceleration without giving the sense of incompatibility on the automatic deceleration by providing a specific deceleration step-setting tool to the automatic deceleration unit.

This tractor is equipped with a running speed setter that can set the running speed of the tractor stepwise, a working clutch intervening into the working part power transmission route and an automatic deceleration unit that is interlocked with the clutch-off operations of the working clutch to automatically decelerate the running speed. Further, this automatic deceleration unit is equipped with a specific deceleration step-setting tool that can convert the automatic deceleration based on the present running speed into the step number according to the step-setting tool. In a preferred embodiment, a deceleration-actuating mechanism is intervened between the running speed setter and a running speed transmission device to change the transmission position of the transmission device relatively to the operation position of the running speed setter.