PURPOSE: To contrive stabilizing of height of a working device fitted on a rear part and stabilizing of field-leveling performance with sensor floats in inclining of a machine bed plate simultaneously in two directions to before and behind and to right and left.

CONSTITUTION: This working machine has sensors 28 and 29 detecting inclination of a machine bed to before and behind direction and to right and left direction. Sensors 28 and 29 and a driving device are connected through a controller 30. The sensors 28 and 29 detect inclination to before and behind direction of the machine bed and a pair of driving devices transfer each rear wheel to the same direction and recover the inclination of the machine bed horizontally, and detecting inclination to right and left direction, a pair of driving devices transfer each rear wheel to the reverse direction to recover the inclination, and in a case of simultaneously detecting a before and behind inclination and a right and left inclination, a pair of driving devices transfer each rear wheel to the same direction and recover the before and behind inclination of the machine bed preferentially.