To store a matter to be stored under a strict temperature control by providing a sealed space for storage defined by a partition wall containing a latent heat storage material in a storehouse body.

A panel 1 has a structure wherein a plurality of packs 3 having a latent heat storage material built therein and comprising water, a sodium carbonate water solution, a calcium chloride water solution, an ammonium chloride water solution and the like are sandwiched between metal plates 2 on both sides, and a storage container 4 as a cubic box-like closed space is constituted of the panels 1. A plurality of the storage containers 4 are disposed in a storehouse body such as refrigeration storehouse or the like so as to constitute a constant temperature storage storehouse. By this constitution, storage object matters 5 stored in the storage container 4 can be stored under a strict temperature control so that deterioration in quality of the matters 5 can be prevented.