To improve the resilience without impairing durability.

The iron golf club head 1 has a top face TP forming the top surface of the head, a sole face SO forming the undersurface of the head and a face part FP which is enclosed with the top face TP and a toe face TO joining the top face TP and the sole face SO on the side of the head's tip while its front makes a face F. The face part FP comprises a thick part 5 formed on the central side and a thin part 6 which encloses the perimeter of the thick part 5 while being made thinner than the thick part 5. The thick part 5 is made flat at a ratio (H/W) of 0.1-0.4 between the maximum length W in the direction of the toe to heel and the maximum length H in the direction of the top to sole along the face F under the reference state that the head is placed on a horizontal plane HP at prescribed lie and loft.