PURPOSE: To cut a resin by a gate hole section at the time of pin-point gate cutting, to generate a plurality of notch effects in a cut section and to reduce the residual height of a gate by forming the shape of the gate hole in a plural- arcuate connecting gate hole formed by a reference circle and a plurality of circles crossing with the reference circle.

CONSTITUTION: A stationary side mold 1 and a movable side mold 2 are superposed and a cavity 4 having a product shape is formed. The cavity 4 is filled with a resin from a gate 3, and the whole is separated into a product and a runner formed to the gate 3. The plane shape of the gate hole 6 of the gate 3 is formed in a plural-arcuate connecting gate hole 6 formed by a reference circle 6a and three circles 6b crossing with the reference circle When the molds 1, 2 are opened and the product is extracted, the resin in the gate 3 is cut from the gate hole. The height of a gate residue 7 at the time of the extraction of the gate 3 can be lowered by notch shapes at a plurality of positions at the time of the cutting, thus preventing the generation of nondefectives even in thin products.