A light emitting unit 200 of a light irradiation device is provided with: a substrate on which a plurality of light emitting elements are arranged； and, when a direction perpendicular to an arranging surface of the substrate is referred to as upper-lower direction, and the side on which the plurality of light emitting elements are arranged is referred to as "upper", a lower case disposed under the substrate. Each of the plurality of light emitting elements is arranged such that the optical axis thereof is inclined from the upper-lower direction. The lower case includes a receiving portion for supporting, from diagonally below, each of the plurality of light emitting elements arranged on the substrate.本發明的課題在於提升用以將光線照射至人體的被照射部位之光照射裝置的功效。光照射裝置的發光部200係具備有：基板，係配置有複數個發光元件；以及下側殼體，係在將與基板的配置面呈鉛直的方向稱為上下方向且將配置有複數個發光元件的一側稱為上側之情形中設置於基板的下方；複數個發光元件各者係以光軸從上下方向傾斜之方式配置；下側殼體係具有：承受部，係從斜下方支撐配置於基板的複數個發光元件各者。
