Abstract: An insole capable of transmitting a force of tiptoes to a shoe sole and also capable of enhancing muscle strength of toes and a foot sole. An insole includes: an insole main body adapted to be accommodated in a bottom of a shoe; a thong attached to a toe-side front part of the insole main body; and an instep-side support provided at an end of the thong opposite to the insole main body and extending in a front-rear direction from a toe side to a heel side with respect to the thong, wherein a relationship SL?KL is satisfied, where SL is a length of the instep-side support from a center of its part contacting the thong to a toe-side end part, and KL is a length from the center of its part contacting the thong to a heel-side end.