A construction component forms at least a part of a structure that faces a target space. The construction component has a first function, a second function, and a third function. The first function is a function of emitting illumination light toward the target space. The second function is a function of allowing incident light to enter the construction component. The incident light is emitted from a light source disposed out of a projection area, viewed from the target space, of the construction component and is incident on the construction component via a light transmission member. The third function is a function of converting the incident light into the illumination light.