A decorative light-transmittance sheet type key top of a pushbutton that presents an uniform, massive and brilliant luster, to not take much working time in production, and to aim at a simplification of the work process, which is integrally formed with a transmittance plastic film curved according to the shape of a top face side of the key top body, a decorative transmittance key top is constituted to reflect selectively light with a given wavelength and present transmittance brilliant color by providing cholesteric liquid crystal layer made of liquid crystal polymer on a surface side and/or the back side of the film, and a manufacturing method thereof.