PURPOSE: To provide a low temperature chamber in which a plurality of storing chambers having different temperature ranges can be constructed within one low temperature chamber with a fusional latent heat of cold heat accumulation agent.

CONSTITUTION: An inside part of a thermal insulating box 3 is divided into an upper part and a lower part by a thermal insulating partition wall 7 so as to constitute storing chambers 8 and 9. Cold heat accumulation agent 18 is stored in the lower storing chamber 9. There is provided a blower 23 for use in circulating cold air within the lower storing chamber 9 in the lower storing chamber 8. There is also provided a battery cell 14 for supplying electricity to the blower 23. There is provided a storing chamber thermostat 26A for controlling an operation of the blower 23 in response to a temperature within the upper storing chamber 8. An applied temperature range within the lower storing chamber 9 is the lowest temperature range within the thermal insulating box 3 and then the cold heat accumulating agent 18 is set to be corresponded to the temperature range.