The light irradiation to the desired region is surely and easily performed while preventing the light irradiation to the region other than the desired region on the skin. The light irradiator (1) includes a light source that irradiates light to the skin, a light shielding member (3) disposed between the skin and the light source, and a flexibility in which the light source and the light shielding member (3) are mounted. The light shielding member (3) can be formed with an opening (9) corresponding to a specific region (8) in the skin, and the light can be opened ( 9), and a specific area is irradiated.皮膚における所望の領域以外の領域への光照射を防止しつつ、該所望の領域への光照射を確実かつ簡易に行う。光照射器（１）は、皮膚に光を照射する光源と、皮膚と光源との間に配置される光遮蔽部材（３）と、光源及び光遮蔽部材（３）が搭載された可撓性を有する基台と、を備えており、光遮蔽部材（３）には、皮膚における特定の領域（８）に対応した開口部（９）を形成することが可能であり、光は開口部（９）を通過して特定の領域に照射される。
