To provide a lighting device for a time indication panel of a clock, which can be prepared for a digital clock or can additionally be installed in an existing clock and is excellent in electric power saving nature.

The lighting device of the clock includes a magnet drive unit, a magnetic detector, a light intensity detector, a splicing switch, and a luminescent drive unit. The magnet drive unit has a circumference moving magnet to output the magnetic detection signal, when the magnet reaches a magnetometric sensor position in the magnetic detector. Further, the unit outputs an optical sensor for the light intensity detector, and a darkness detection signal. The connecting switch makes turning on electricity splicing of the splicing switch at a luminescent drive with the magnetic detection signal and the darkness detection signal. The illuminant drive unit lights the illuminant charging capacitor when turning ON of the splicing switch, and the illuminant is made into the lighting device of the clock made to light until the charging current of the condenser is lost when turning OFF of the splicing switch.