Patent ID: 8747251

Claim:
A hollow golf club head having a volume equal to or greater than 400 cubic centimeters and comprising: a crown; a sole; and a continuously extending rib (X) having a mean value of a width, BR, equal to or less than 2 millimeters and a weight equal to or less than 5.0 grams, wherein the rib (X) is provided on an inner surface of the head; the rib (X) is substantially parallel to a toe-heel direction; and when a maximum amplitude of vibration in a first-order mode in a state where the rib (X) is removed is defined as Ma 1 and an amplitude ratio with respect to the maximum amplitude Ma 1 is defined as Rh (%), disposal of the rib (X) satisfies the following items (a), (b), and (c): (a) the rib (X) crosses at least one of high Rh regions having the amplitude ratio Rh of equal to or greater than 80%; (b) no region having the amplitude ratio Rh of equal to or greater than 60% exists on a toe side than the rib (X); and (c) no region having the amplitude ratio Rh of equal to or greater than 60% exists on a heel side than the rib (X); and wherein the plurality of high Rh regions exist and the rib (X) crosses all of the high Rh regions.