By forming a ground contact edge side of lug grooves such that the groove depth becomes shallower in groove depth from the tire equatorial plane side toward the ground contact edge, and by setting an average angle of inclination formed between a tread face and a groove bottom to be not more than 5°, water expulsion is performed smoothly in the vicinity of the ground contact edge while securing the rigidity of land portions in the vicinity of the ground contact edge. This enables a high degree of both wet performance and dry performance to be achieved.