A heat transfer sheet adhering apparatus, for adhering a heat transfer sheet to a ring-shaped member adapted to be used in a substrate processing apparatus, includes a heat transfer sheet mounting part configured to mount the heat transfer sheet thereon; a ring-shaped member supporting part configured to support the ring-shaped member; and a vertically movable pressing part configured to press the ring-shaped member supported by the ring-shaped member supporting part against the heat transfer sheet mounted on the heat transfer sheet mounting part. The pressing part is configured to press the ring-shaped member gradually from an inner peripheral side to an outer peripheral side of the ring-shaped member or from the outer peripheral side to the inner peripheral side of the ring-shaped member.