PURPOSE: To solve the jetting and eliminate the filling time difference among respective cavities by a method wherein the volume of a material reservoir provided at the final end of a runner having a plurality of cavities is made variable by means of an adjusting pin and at the same time a flow rate limiting pin, the protrusion of which into the runner is made variable, is provided.

CONSTITUTION: A vertically movable adjusting pin 7 is provided on the bottom of a material reservoir 6 so as to make the volume of the material reservoir 6 variable. Further, a flow rate limiting pin 4, which protrudes between the final cavity Cn and the material reservoir 6 is made vertically slidable so as to adjust the gap width of a gap part 8. The width of the gap part 8 and the volume of the material reservoir 6 are adjusted in accordance with the difference in the characteristic properties of resins and the difference in molding conditions. When resin begins to pour in the final cavity Cn, the resin blows into the material reservoir 6 little by little through the gap part 8, resulting in generating no jetting at the final cavity Cn and enabling to prevent voids, thin spots, nonuniformity and the like from generating and to make the filling time difference among the respective cavities C1...Cn smaller than ever.