Provided is a simple light irradiation apparatus capable of performing uniform irradiation even on to a treatment area having a curved surface and capable of suppressing excessive heating caused by light irradiation. The light irradiation apparatus (10) includes a polymer gel layer (3) that covers the treatment area (2) on skin (1), an LED protective layer (6) that closely adheres to the polymer gel layer (3), and a substrate (5) on which LEDs (4) closely adhered to the LED protective layer (6) are arranged thereon. A current control apparatus (8) which lights the LEDs (4) controls irradiation intensity and stops irradiation when reaching a demanded dose amount.