A pulley structure includes a cylindrical outer rotation body, an inner rotation body, and a pair of bearings which is disposed between the outer rotation body and the inner rotation body. Of the pair of bearings, one bearing is a sliding bearing, and the other bearing is a rolling bearing. The sliding bearing is made of a thermoplastic resin and is formed into an ended ring shape. A thickness of the sliding bearing at each of both circumferential end portions is smaller than a reference dimension of a thickness of the sliding bearing.