To extend the flying distance of a ball without altering a shape or material for a face of a head.

A hollow passage 24 from a grip to a head 12 through a shaft is formed inside a golf club, and an iron ball 28 is put inside thereof. The hollow passage 24 reaches a sweet spot 20 in the face for a head 12. The iron ball 28 is situated at the extremity of the grip when the swing is at the top (i.e., at the lowest end of the golf club when the swing is at the top), and reaches the sweet spot 20 at high speed due to the centrifugal force at the impact so as to increase the stroke power applied to a ball.