Abstract: A sheet type key top of a push button switch which is disposed over a switch contact used for the input portion of a portable electric appliance or a machine control portion or the like, and through which the underlying switch is depressed to turn it on or off. A film on key tops is formed with a multi layered elastic film (4), and a display portion printed layer (3) is completely covered with the protective layer (4). Then, thermoplastic fine powder (5) capable of heat fusing is added to the display portion print layer (3) and/or to the protective layer (4), thereby the film and the display portion are integrally united by heat fusing a thermoplastic substance constituting key tops and the thermoplastic fine powder through heat generated during molding process. Further, stress intercepting zones of concave or convex shapes are disposed at distances between adjacent keys to prevent error activation.