PURPOSE: To enable the molding of a scale plate with a high plane accuracy having a protruded scale part of the surface thereof, by inserting a thin surface layer paper into a die to do an injection molding.

CONSTITUTION: A thin surface paper 5 formed in a shape of a specified scale plate is inserted into dies 11 and 12 of an injection molding machine and a melt resin 6a is injected into the dies 11 and 12 to mold a base 6 integral. The surface layer paper 5 is bulged into a die scale recess part 12a at the part corresponding to a scale by a resin injection pressure during the molding to the base to obtain a scale plate 7 having a protruded scale part 5a made up of bulged projections of the surface layer paper on the surface thereof. After the molding, a molding takeoff unit with a vacuum suction type sucker between the dies 11 and 12 is advanced and the scale plate 7 is sucked to be taken out between the dies 11 and 12. This facilitates the die release of the scale plate 7 making it easy to take out without firm sticking of the resin 6a to the inner surface of the die 12.