PURPOSE: To remarkably simplify continuous injecting process by leading the insert forming using sheet.

CONSTITUTION: A push button main body 7, which is slectively moved between two positions for switching operation, is inserted into a fixed frame, and an inscription layer 8, which is formed of a transparent protecting layer 9 and an inscription layer 10 formed as the back side layer and formed with various inscriptions in the back surface side of the protecting layer 9, is positioned in a main body 7. The inscription layer 8 is pushed to the main body 7 by a movable frame so as to adhere the printed layer 10 to the main body 7, and heat is supplied to the adherence surface of the printed layer 10 and the main body 7 so as to thermally fuse the protecting layer 9 and the main body 7 through the printed layer.