To provide an in-shoe cleaning system including a light source device with safety taken into consideration, for in-shoe cleaning.

An in-shoe cleaning system includes: a light source device 100 to be inserted into a shoe where a liquid containing photocatalyst particles obtaining a photocatalytic activity by a visible light is sprayed; and a sprayer for spraying a photocatalytic solution obtaining the photocatalytic activity by a visible light to the inside of a shoe. The light source device 100 includes: a light emitting element storage part 10 stored with LEDs 20; and a battery storage part 30 for storing a battery for the LEDs 20. In the light emitting element storage part, a housing includes a base material with translucency, and a prescribed interval is arranged between the housing and the light emitting element.