In a light irradiation apparatus, an elongated body has flexibility that allows for elastic restoration. An LED chip is closely fixed to a tip portion of the elongated body and emits ultraviolet light. A cover unit covers the LED chip so as to protect the LED chip and allows the ultraviolet light emitted by the LED chip to pass through the cover unit. A conductive unit extends in a longitudinal direction of the elongated body and passes electric current for allowing the LED chip to emit light. An insulation unit covers the conductive unit so as to ensure electrical insulation of the conductive unit.