To stabilize the directionality of a hit ball by optimizing the ratio of the moment of inertia acting perpendicularly on the face of a wood golf club head at the time of an impact to the moment of inertia around a shaft in order to improve a head turn at the time of swinging.

An axis passing through the center of gravity G perpendicular to the ground in the case where the wood golf club head is set at a prescribed lie angle θ and a prescribed loft angle δ on a flat surface is rotated by the loft angle γ so as to be parallel to a face. The moment of inertia around the rotated axis is set to be 0.06 to 1.00 times the moment of inertia around the shaft.