A backlighting element 13 includes an EL panel for illuminating the back of a display unit 11, to thereby provide a good viewing. A control unit 16 sends an instruction to a backlight driver 14, and intermittently drives the backlighting element 13 at appropriate timings, or temporarily stops the driving of the backlighting element 13 in synchronism with operation timings of a radio processing unit 17. The radio processing unit is adversely affected by noise generated when the backlighting element is operated. A light storage member is provided on the backlighting element 13 or in its vicinity. With provision of the light storage member, the lighting time of the backlighting element is reduced. When the backlighting element is lit off, the user is not put to inconvenience.