Sole plate producing method

Disclosed is a sole plate production method, which comprises the steps of heating a sole-plate substrate material made of thermoplastic resin, pressing the heated substrate material relative to a foot sole of a human to prepare a sole-plate substrate (1) having a shape corresponding to a sole arch of the foot sole, and producing a sole plate using the obtained substrate (1). In this method, the step of pressing the heated substrate material relative to the foot sole includes pushing in a portion of the substrate material corresponding to an apex of a lateral arch of the sole arch to allow the substrate to be formed with a convex portion (2) corresponding to the apex of the lateral arch. The method of the present invention makes it possible to efficiently produce a sole plate having the convex portion conformable to an apex of a lateral arch of a foot sole.