To keep temperature and humidity of a storage chamber satisfactory.

A cooling pipe 16 of a cooling apparatus is wound on the top of an inner box 12, and in a storage chamber 11 there are removably disposed separation fences 24a to 24d for separating an accomodated article such that it is prevented from making contact with a side wall of the inner box 12. A first heater 23 is provided at a lower portion of the inner box 12 with which temperature in the storage chamber 11 is raised when environmental temperature is lowered. A water conduit 25 is provided in the inner box 12 for guiding condensation W, and an inner reception pan 26 is disposed on the upper part of a machine chamber 14 for collecting the condensation W from the conduit 25, and further a second heater 29 is provided for heating the inner reception pan 26. Cooling power of the cooling apparatus and thermal loads of a box, a cover, and stored articles are set such that interruption time of the cooling apparatus is longer than the working time to keep humidity of the storage chamber 11, and the condensation W in the inner reception pan 26 is evaporated with the second heater 29 to raise the humidity of the inner box 12.