PURPOSE: To prevent derailment of a crawler belt and to facilitate running on a rail in a crawler type working machine provided with an upper turning body having various working equipment by forming a groove in which the rail of a track is fitted on an outer circumferential surface of a crawler shoe constituting the crawler belt.

CONSTITUTION: A crawler belt 6 is attached to both sides of a base frame 3 through a drive tumbler 4 and an idle tumbler 5. In a working machine in which an upper turning body 2 is mounted on a crawler type lower running body 1 in capable of turning and various working equipment is attached on the upper turning body 2, a groove 9 in which a rail 8 of a track is fitted is formed on an outer circumferential surface of each of crawler shoes 7 of a crawler belt 6 in which a large number of track links are connected in the endless state and the crawler shoe 7 is separately bolted to each of the track link. This groove 9 is formed by providing projections 10 and 11 with a proper interval on the outer circumferential surface of the crawler shoe 7. And the track is repaired while the crawler belt 6 is circulated and made to run on the rail 8 in the state where the groove 9 formed on this crawler belt 6 is fitted in the rail 8.