To provide the mounting structure of a cab, which restrains vibration from being transmitted from a car body frame to the cab without spoiling the function of a torsion bar.

The mounting structure of the cab 2, which can be set to a tilt position and non-tilt position, and the rear end side of which is supported from below by the car body frame 4 at the non-tilt position, includes: a fixed end part which is supported by the front end of the car body frame 4 in such a state that the relative rotation to the car body frame 4 is restricted; and a free end part 73 the relative rotation of which to the car body frame 4 is not restricted. The mounting structure of the cab 2 further includes: the torsion bar 7 extending in the vehicle width direction; and a lever 8 extending to the rear part of the vehicle from the free end part 73 in such a state that relative rotation of the lever to the torsion bar 7 is restricted. The lever 8 has an acting part 84 which is pressed down to the rear end side of the cab 2 descending to the non-tilt position and descends to an acting position. The torsion bar 7 is twist-deformed according to the descending of the acting part and the acting part 84 at the acting position transmits torsional reaction force of the torsion bar 7 to the rear end side of the cab 2 so as to push up the cab 2 from below.