A mold includes a seat, a plurality of guiding tracks, a plurality of positioning grooves, a plurality of telescopic rods, a plurality of elastic members, at least one sliding device and an insole material. The guiding tracks are disposed on the seat. The positioning grooves are disposed on the seat and are corresponding to the guiding tracks, respectively. The telescopic rods include a plurality of abutting portions, respectively. The elastic members are disposed in the seat for applying a plurality of restoring forces to the telescopic rods, respectively. The sliding member is movable along the track to press the abutting portions, and the abutting portions are connected tightly to each other so as to position the telescopic rods. The insole material is disposed below the telescopic rods for molding an insole.