PURPOSE: To manufacture even the injection molding shoe having the comparatively thick instep by using a conventional side mold whose mold does not change by thinning at least the peripheral edge part of the lower part of the instep to prescribed thickness by press working.

CONSTITUTION: At least the lower part peripheral edge part 11 of the instep 10 is thinned to prescribed thickness by press working. Thereafter, a body last 30 which hangs in this instep 10, a side mold 20 and a bottom mold 40 are fitted by forming a sole molding cavity 50 in the inside. In this case, the lower part peripheral edge part 11 of the instep 10 hung into the body last 30, and also, adjusted as to its thickness is pressed against a fitting projecting part 21 provided peripherally on the inside face 20a of the side mold 30. Subsequently, by injecting a sole molding material Z into this sole molding cavity 50 and executing the injection molding of the sole formed integrally with the lower part of the instep 10, and injection molding shoe is manufactured.