A white light source system being an illumination light source for a variety of target objects, such as exhibits in an art gallery, that require high color-rendering properties similar to natural light and being capable of: taking into consideration regional and time differences and reproducing sunlight shone on to earth; and being capable of radiating white light having reduced ultraviolet or blue light-emission components that may have an adverse impact on paintings, etc. The white light source system uses at least four types of white light sources including a combination of ultraviolet and violet light-emitting LEDs and phosphors. As a result of adjusting types of phosphor material used and the mixing proportions for the white light sources, the white light source system continuously reproduces daily changes in sunlight for a specified season and a specified region and reproduces a white light that takes safety issues into consideration by improving a device structure.