A keypad lighting device includes: a keypad member formed by an arrangement of plural key tops; at least one light emitting device arranged below the key pad member; and a light guide plate member arranged below the keypad member to light the key tops with light projected from the light emitting device. The light guide plate member is formed with at least one light-incident surface, to which the light projected from the light emitting device is incident. The light-incident surface is formed by a curved surface or plural inclined surfaces, and at least one of the normal lines of the light-incident surface is arranged to pass through the light emitting surface of the light emitting device.