To provide a V-belt pulley which can constantly maintain a tension at low cost.

The V-belt pulley 1 transmits power to auxiliary machines of an automobile engine through a V-belt 2, which is fixed to a bearing 6 for receiving a rotary shaft 5. As shown in a cross section cut by a plane including a rotary shaft center 4, this V-belt pulley 1 is a ring body comprising three sheets of plate like ring bodies being a large diameter part 8, and two sheets of plate like ring bodies being a small diameter part 10, both of which are alternately-joined in layers in a rotary shaft direction. Among these five sheets of plate like ring bodies comprising the large diameter parts 8 and the small diameter parts 10 that form the V-belt pulley 1, only the engine side large diameter part 8a located on engine side has a cantilever structure fixed to the bearing 6. Further those large diameter part 8 and small diameter part 10 are respectively made of members different from each other, and thermal expansion rate in a rotary shaft direction of the small diameter part 10 is larger than that of the large diameter part 8.