Abstract: To provide an insole that promotes maintenance of the inclination angle and rotation of a motion axis, which is a rotation axis of the inside of both feet, in a golf swing. By making the thickness of the insole the lowest at the base of the thumb (A), and then gradually increasing the thickness from the medial heel (B), lateral heel (C), and little finger base (D), the thickness of the insole is the lowest, and the thickness is gradually increased to the base of the little finger (D). By maintaining the inclination angle of the ball of the foot and preventing the ball of the foot from lifting due to centrifugal force caused by the swing, the center of gravity is prevented from moving toward the little finger, and smooth rotation from the ball of the foot is promoted.