An ultraviolet sterilization device 10 includes a processing chamber 12 that houses a subject of sterilization and a light source 40 that irradiates an interior of the processing chamber 12 with ultraviolet light. A wall of the processing chamber has a stack structure including a first layer made of a fluororesin material and a second layer made of of an ultraviolet reflective material, the first layer being provided on the inner side of the processing chamber. The light source 40 includes an aluminum gallium nitride (AlGaN) based ultraviolet light emitting device.