A hollow wood-type golf club head with improved directional stability having, in head periphery region Ao including head contour line OL defined by crown portion 4 when viewed from above as a plane view of the head in the standard state, thick wall portion 9 extending along the contour line and expanding toward the hollow portion side to have an increased thickness, wherein the thick wall portion 9 comprises crown thick wall portion 9c which forms a part of crown portion 4 and has a thickness of 1.2 to 2.0 mm, and side thick wall portion 9s which is continuous with the crown thick wall portion 9c and forms a part of side portion 6 and has a thickness of 1.2 to 3.0 mm, and wherein the thick wall portion 9 has a width along the head outer surface of 6 to 16 mm in a vertical section passing through the head center of gravity G in the standard state.