A golf club head is provided with a crown, a sole, and a continuously extending rib (X). The rib (X) is provided on an inner surface of the head. Preferably, the rib (X) is substantially parallel to a toe-heel direction. When a maximum amplitude of vibration in a first-order mode in a state where the rib (X) is removed is defined as Ma1 and an amplitude ratio with respect to the maximum amplitude Ma1 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).