To maintain the freshness of food in a food container even if it is maintained at the normal temperature or in a refrigerator for a long period of time and easily remove impurities attached to the surface of the container.

In a container 1 with bottom constituting a food container, powder of sansenseki is mixed into a transparent body such as resin or glass which transmits visible rays to keep the transparency at a certain level. Since the sansenseki is in the form of powder, it has a very large specific surface area and far-IR rays emitted from the powder pass through a transparent body and are emitted to the outside of the body (inside a food container, and outside a food container). As a result, food stored in the food container is subjected to the effect of sansenseki so that bacteria are restrained from proliferating and the freshness of food can be maintained for a long period of time.