To provide a means without using energy for storing an unprocessed food material such as vegetables and fruit for a long time without deteriorating their freshness.

This storage case A comprises an outer layer 1 made of a metal, etc., having a shape keeping property, an inner layer 2 made of a permeable member and an activated member 10 to be placed between the outer layer 1 and the inner layer 2. The activated member 10 is either a sheet shaped or panel shaped porous ceramic or activated charcoal. The activated charcoal 10, which removes ethylene from the environment by either absorption or decomposition, prevents plant foods from ripening or sprouting. Utilizing this mechanism, the freshness of the plant foods is maintained. When the function of the member 10 becomes deteriorated, because the member 10 is taken out for replacement with a new one, the recovery of freshness keeping function is easy. The food material stored and the member 10 do not touch, which makes it hygienic visually and practically.