PURPOSE: To realize a thin molded matter in a continuous form or curved form by a method wherein the movability between the molded part and its inner part is maintained and the distortion, offsetting, or squeezing-out of the integrally molded inner part are prevented from developing due to molding injection pressure and pressurizing force.

CONSTITUTION: Within a mold 1, fixing pins 2 are erected along a continuous length or curved form so as to fix a piano wire, rigid material or heating wire 3 to the fixing pins 2.