A putter head prevents a ball from sliding over a green while maintaining golfers' preferred hitting feel and roll of the ball. A face insert fitted in a face of the putter head has an outer layer which serves as a ball-hitting surface and an inner layer which is located on an inner side of a head body. A smash factor of a second polymer material forming the inner layer is greater than a smash factor of a first polymer material forming the outer layer. Two types of groove, grooves of a first groove group and grooves of a second groove group are formed in an external surface of the outer layer. The grooves of the first groove group may be 0.25 to 1.6 mm wide and 0.05 to 0.5 mm deep and the grooves of the second groove group may be 0.075 to 0.5 mm wide and 0.025 to 0.1 mm deep.