Vertical planes equally dividing space between a position of the shaft-hole axis of a head to a rearmost point of the head are defined as first vertical plane S1 to fifth vertical plane S5 starting from a face side. In a view showing a second contour R2 and a fourth contour R4 in overlapping relation, the second contour is defined by an intersection of the second vertical plane S2 and a head outside surface, and the fourth contour is defined by an intersection of the fourth vertical plane and the head outside surface. In this overlap view, toe-1 point t1 to toe-8 point t8are defined on a toe-side line portion of the second contour R2. Toe-side gaps T1 to T8 between the second contour R2 and the fourth contour R4 with respect to the respective points t1 to t8 are defined according to predetermined specifications.