A golf club head includes a face including a bulge formed at the center of
a backside thereof and having a thickness of 2.0 or more times the
thickness of the thinnest part, and a plurality of ribs extended from the
bulge toward a circumference of the face. Six or more ribs are provided
as the plural ribs and an angle .theta.(.degree.) formed between
extension directions of a respective pair of adjoining ribs is less than
90.degree.. The maximum thickness of the bulge is not more than 3.5 times
the thickness of the thinnest part.