The computer of the present invention is provided with a main body on which keys to be operated by the user are disposed and a display unit that displays an image in accordance with each operation executed for the main body. Each key disposed on the main body is composed of its body having a key top and a light accumulator recess opened in the key top. The light accumulator recess is formed in a manner indicative of the character or symbol associated with such key. The light accumulator recess has embedded in it a light accumulating material such that the character or symbol associated with the key is illuminated by the residual light emission of the light accumulating material when the computer is operated in a location with little or no ambient light.