PURPOSE: To obtain an injection-molded product without roughness on the surface of letter-portion by introducing synthetic resin from gates by way of a subrunner into each cavity on a base body in which cavities for a plurality of letters and marks are formed.

CONSTITUTION: A base body 25 consisting of soft elastic synthetic resin is injection-molded, and on said base body 25, the cavities 23 which are directed for a plurality of letters and marks and are respectively provided with pouring holes 22, are prepared. The base body 25 is set is a metal mold, and synthetic resin is injected from an injection-molding machine. Injection-material is introduced into each pouring port 22 by way of a subrunner 29 which communicates gates 28 and pouring ports 22, from a sprue 26 a runner 27 and three gates 28, thereby injection-molding the letters and the marks by filling each cavity 23. Consequently, the injection pressure is caused to be uniform, and the injection-material is filled uniformly in each cavity 23. Accordingly, the roughness which is caused to occur by unsufficient filling or excessive filling on the surfaces of the mark portions, is reduced.