The present invention relates to a pulley structure containing a first rotatable body, a second rotatable body and a torsional coil spring, in which the torsional coil spring has one end region, the outer circumferential surface of which is in contact with one rotatable body due to the self elastic restoring force when the pulley structure is in a stopped state, the other end region, the inner circumferential surface of which is in contact with the other rotatable body when the pulley structure is in the stopped state, and a middle region, and in which when the torsional coil spring is twisted in the diameter increasing direction, the inner circumferential surface of at least a circumferential portion of the other end region of the torsional coil spring separates from the other rotatable body.