PURPOSE: To prevent air stagnation from occurring and design omission from occurring at the time of the use of a carapas with inferior ventilation by providing a burr hole which communicates from near the lower side of the abutting edge of a last mold and a side mold to a mold external side.

CONSTITUTION: Plural burr holes 6 are formed so as to be tapered from upper surfaces 10 of side modes 4a and 4b through mold internal surfaces to a part facing from abutting edges 9 of a last mold 2 to lower side neighboring parts along the abutting edges 9 of the mold 2. Further, at a pair of the right and left side molds 4a and 4b, a bank 7 is provided on an inner position than an opening 11 of the burr hole 6 on the upper surface of the side molds over the hole abutting edges 9 of the mold 2. In the sole forming mold 1, a sole molding cavity 5 is formed by the molds 2, 3, 4a and 4b, a carapas 8 is slung into the mold 2, and successively, a resin material for the sole is injected to the cavity 5 of the mold 1 to fill the cavity.