A golf club head includes a first portion forming a part of the head body of the golf club head, a second portion forming another part of the head body of the golf club head, and an intermediate layer. The first portion, the second portion, and the intermediate layer are made of different materials. Each of the first portion and the second portion has an abutting portion, with the intermediate layer being positioned between the abutting portion of the first portion and the abutting portion of the second portion. The intermediate layer and the abutting portion of the first portion are joined together by friction welding, and the intermediate layer and the abutting portion of the second portion are joined together by friction welding, thereby forming a golf club head product