A face backside of a golf club head is provided with six or more ribs extended from a face center toward face circumferences. Angles .theta.1 to .theta.6 between respective pairs of adjoining ones of the ribs are less than 90.degree.. One of the ribs that form the smallest angle between its extension direction and a head vertical direction d1 and that extends from the face center toward a crown-side face circumference constitutes an upward rib, which has a smaller cross-sectional area than any of those of the other ribs.