A semiconductor light emitting device includes an LED chip, which includes an n-type semiconductor layer, active layer, and p-type semiconductor layer stacked on a substrate. The LED chip further includes an anode electrode connected to the p-type semiconductor, and a cathode connected to the n-type semiconductor. The anode and cathode electrodes face a case with the LED chip mounted thereon. The case includes a base member including front and rear surfaces, and wirings including a front surface layer having anode and cathode pads formed at the front surface, a rear surface layer having anode and cathode mounting electrodes formed at the rear surface, an anode through wiring connecting the anode pad and the anode mounting electrode and passing through a portion of the base member, and a cathode through wirings connecting the cathode pad and the cathode mounting electrode and passing through a portion of the base member.