To maintain the utility of a stroboscopic device, and to install more circuit components in a compact state.

The stroboscope unit 17 is constituted of a stroboscope main substrate 17a with a main strobe circuit for emitting light by a fixed quantity and a stroboscope sub substrate 17b with a strobe light control circuit. A main capacitor 38 is mounted on the stroboscope sub substrate 17b, then, a main capacitor unit 48 is formed. The stroboscope sub substrate 17b is attached to a discharge tube case 40 through a holding plate 41 so as to impart a light control function to the constant-emission stroboscopic device arranged on the stroboscope main substrate 17a. Besides, the constant-emission stroboscopic device is obtained by detaching the main capacitor unit 48 from the stroboscope main substrate 17a and attaching only the main capacitor 38.