To provide a wheel device capable of smoothly rolling and raising auxiliary wheels abutted on a step wall surface upwards when going over a step, for the wheel device used for an attachment object moved by pushing or pulling an operation member.

When a traveling body 5 is in a travel posture and a swing arm 6 is supported at a standby position by a second auxiliary wheel 8, a first auxiliary wheel 7 disposed closer to the front side than is a front wheel 3 collides with a step wall surface SW first, and is rolled upwards, raised and moved on the step wall surface SW. By the raising movement, the swing arm 6 is raised and swung from the standby position to an upper limit position and stopped at the upper limit position by an upper limit stopper 10A. In the state, when an operation handle 92 is pulled further to a front oblique upper side, the front wheel 3 of the traveling body 5 is separated from a traveling plane and floated so that it becomes easy to make a wheel device 1 go over a step.