A climbing device body (21) can assume by a rotation operation an erect, retracted position allowing a first end portion (21A) to be positioned above and a second end portion (21B) to be positioned below and a tilted, deployed position allowing the second end portion (21B) to be positioned sideways of the vehicular body outer than the first end portion (21A). A handrail (22) is engaged with the rotation operation to be capable of assuming a raised state allowing a gripping portion (22a) to assume a first position distant from the climbing device body (21) in a deployed position and a folded state allowing the gripping portion (22a) to assume a second position close to the climbing device body (21) in a retracted position.