Provided is a turbine blade which makes it possible to reduce total pressure loss in the tip-side blade cross-section of a turbine rotor blade and suppress performance degradation even when cooling air is entrained therein. A turbine rotor blade which is attached to a rotor and forms a turbine cascade that rotates within a stationary member, wherein a platform part which forms a gas passage through which a mainstream gas flows, and an airfoil part which extends in a radial direction perpendicular to the rotating shaft of the rotor from a gas passage surface that is a surface forming the gas passage of the platform part are provided, the turbine rotor blade being formed such that a gap between a tip-side end surface that is an end surface on the leading end side of the airfoil part and the stationary member facing the tip-side end surface is smaller on the downstream side than the upstream side in the flow direction of the mainstream gas.
