An optical element module includes a casing having a bottom plate, a temperature-adjusting unit being mounted on the bottom plate in the casing and having at least a lower layer portion and an upper layer portion positioned above the lower layer portion, a support member mounted on the temperature-adjusting unit in the casing, and a semiconductor laser element being mounted on the support member and outputting a laser light to a forward side. The upper layer portion of the temperature-adjusting unit projects at a backward side of the semiconductor laser element relative to the lower layer portion.