A low-temperature storage includes: a thermally-insulating casing including an accommodating portion accommodating an item to be refrigerated; a door to be closed in a manner capable of opening/closing the portion; a cooling mechanism cooling an interior thereof; a temperature-detecting unit measuring a temperature in the portion; an opening/closing-detecting unit detecting a door open/close state; and a control unit including a temperature-adjusting unit controlling the cooling mechanism so that the temperature reaches a target temperature, first- and second-temperature-storing units storing first and second temperatures, respectively, a target-temperature-setting unit setting the target temperature at the first temperature when the opening/closing-detecting unit detects that the door has changed from an open to closed state, and thereafter, setting the target temperature at the second temperature, and a control-information-setting unit setting the first or second temperatures, and when a difference therebetween is equal to or greater than a predetermined value, outputting information indicating as such.