An indentation (recess) (20) is formed along the circumferential direction of a rotor on an end face (18) of the trailing edge of a platform (16). An opening (15) for a cooling passage (14) is formed in the outside region (22) of the end face of the trailing edge that is positioned outside this indentation (recess) in the rotor diameter direction. The rotor-diameter-direction thickness (L1) of the outside region in the vicinity of the opening of the cooling passage is greater than the rotor-diameter-direction thickness (L2) of the outside region that corresponds to the trailing-edge end portion of a hub (13) of a wing profile (12) connected to the platform.
