PURPOSE: To illuminate the whole key display part evenly with a sufficient illuminance by dispersing and converging the light from a light source using a diffusion plate, and introducing the light to a transparent click sheet through a transparent lower electrode sheet, electrode contact, and upper electrode sheet.

CONSTITUTION: In an electrode sheet 41, a lower electrode sheet 43 and an upper electrode sheet 42 made of soft, transparent insulative resin are put one over another with a spacer 44 interposed, wherein transparent electrode contacts 45, 45 are furnished on the mating surfaces of these two sheets 42, 43 being composed of the contacts 45, 45, transparent paste, and conductive film and located in the space 44a. A click sheet 46 is embossed at the oversurface of another spacer 47, and a transparent dome-shaped part 46a is adhered to the part over electrode contact 45 and space 47a. An injection molded LED spacer 49 furnished with a diffusion plate 52 is provided on the undersurface of the lower electrode sheet 43. This diffusion plate 52 is formed by adding several tens of % glass powder to polycarbonate, being subjected to a diamond cut process to have light dispersing and converging functions.