Abstract: By providing a compact, easily held carrying case having an elongated recess in one surface thereof in which a thermometer is retainingly placed with said elongated recess incorporating a slotted aperture which is illuminated when desired for reading the thermometer, a unique thermometer carrying case and illuminating device therefore is achieved. Easy access to the electrical energy and the light source is provided by a removable surface on another surface of the carrying case. If desired, the portion of the carrying case juxtaposed above the thermometer may incorporate transparent magnifying material in order to assure easier reading of the thermometer. The illumination system can include reflectors for directing light through the slotted aperture. Also a removable holder for the light source and its source of electrical energy can be provided.