To provide a useful food material storage method obtained by combining natural ice formation and artificial ice formation.

An ice storage chamber of an insulation structure and a storage chamber for storing food materials are disposed, and an upper part and a lower part of each of both chambers are communicated with each other through passages. A circulation fan is disposed in at least one of the passages. An electric cooling apparatus is disposed at a proper location in the ice storage chamber. In the food material storage thus configured, an outside air intake ice formation period and a ventilation circulation period and an operation period of the electric cooling apparatus are repeated, so that cool air in the ice storage chamber is circulated in the storage chamber by driving of the circulation fan.