An item to be preserved is chilled or frozen without causing discoloration or an offensive odor on the item. A refrigeration chamber includes: a refrigeration compartment set at a chilling temperature or a freezing temperature a catalyst-layer forming plate provided along the wall surface of the refrigeration compartment a catalyst layer containing a catalyst prepared by blending photocatalyst particles and metal catalyst particles with a solution of a binder and a binder adjuvant a light source opposed to the refrigeration compartment, the light source irradiating the catalyst layer with light, and item trays disposed in the refrigeration compartment, the item trays acting as plasma plates or having plasma plates thereon, wherein the refrigeration compartment contains a counter electrode plate for the plasma plate.
