A running device includes: a rubber crawler of an endless shape; a guide protrusion disposed in center, with respect to a width direction, of an inner circumferential surface of the rubber crawler; a driving protrusion disposed on each of opposite sides, with respect to the width direction, of the inner circumferential surface of the rubber crawler; and a track roller disposed over the guide protrusion, and configured to roll on the inner circumferential surface of the rubber crawler and to be in surface-contact with a side surface of the guide protrusion and a side surface of the driving protrusion. The track roller has side surfaces disposed on end portions with respect to the width direction, surface-contactable with the side surface of the guide protrusion and the side surface of the driving protrusion, respectively. The side surfaces of the track roller are disposed facing the side surface of the guide protrusion and the side surface of the driving protrusion, respectively, so as to be in surface-contact with the side surface of the guide protrusion and the side surface of the driving protrusion in response to sway of the track roller in the width direction of the rubber crawler.