A crawler produced so as to prevent the occurrence of dislocation of a wheel, stabilize the running of the rotating wheels, minimize the vibrations of the wheels and enable a core bar-containing endless rubber belt to double as an endless iron caterpillar. This crawler is provided with a plurality of outer flange-carrying wheels (3) each of which has flange portions (3b, 3b') projecting from both of the outer side parts of a central inner wheel portion and extending in the radially outward direction, and an endless rubber belt (4) containing core bars (10) therein or a shoe link-carrying endless iron caterpillar (1), which is wrapped around these outer flange-carrying wheels (3). The rubber belt (4) is formed so that the rolling surfaces of the flange portions of the outer flange-carrying wheels contact the exposed shoulder portions (13a, 13b, 13a', 13b') of the core bars (10). The iron caterpillar is formed so that the rolling surfaces (3a) of the central inner wheel portions of the outer flange-carrying wheels contact the upper surfaces of the shoe links.