A crawler includes a crawler main body (a rubber crawler main body (12)), a tensile body (70), guide protrusions (16), and flat surfaces (40). The tensile body (70) is provided with a flat portion (72) that is arranged along a width direction of the crawler main body and a slanting portion (74) that is slanted and arranged at a width direction outer side of the crawler main body relative to the flat portion (72). The guide protrusions (16) are formed at an inner peripheral face of the crawler main body at a width direction middle portion of the crawler main body. The flat surfaces (40) are formed at the width direction outer sides of the crawler main body relative to the guide protrusions (16). Turning wheels (a driving wheel (100), an idling wheel (102) and rolling wheels (104)) provided at a vehicle roll on the flat surfaces (40). In a linear region of the crawler main body as seen in a side view of the crawler main body, if a thickness from an imaginary plane projected from the flat portion (72) in the width direction of the crawler main body to an end edge at a crawler main body width direction outer side of the slanting portion (74) is represented by L, then a result of subtracting a turning direction length of the crawler main body at the flat portion (72) from a turning direction length of the crawler main body at the slanting portion (74) is less than 2πL.