To improve safety of a light irradiation device.SOLUTION: A light irradiation device 100 which irradiates light to a person while an irradiating part 101 having an irradiating region 111 through which light 200 passes is pressed against the person, includes: a light source 102； a contact member 103 provided in the irradiation region 111 and which retracts based on the pressing force of the irradiation part 101； and a control means 104 which irradiates, from the irradiation part 101, the light of a predefined light amount from the light source 102 when the retract distance of the contact member 103 exceeds a predefined value.SELECTED DRAWING: Figure 1【課題】光照射装置の安全性を高める。【解決手段】光２００が通過する領域である出射領域１１１を有する出射部１０１を人に押し当てた状態で人に光を照射する光照射装置１００であって、光源１０２と、出射領域１１１内に配置され、出射部１０１を押し当てる力に基づいて後退する接触部材１０３と、接触部材１０３の後退距離が所定値を超えると、光源１０２からの所定光量の光を出射部１０１から出射させる制御手段１０４とを備える光照射装置１００。【選択図】図１
