PURPOSE: To preserve an ingredient of a plant body for a long period by putting the ingredients, preferably together with a dehumidifying agent and freshness- retaining agent into an air-impermeable vessel and sealing the vessel.

CONSTITUTION: An ingredient (flower, leaf, seed, etc.) of a plant body, especially flower is sealed in an air-impermeable vessel (preferably made of glass) to preserve the ingredient for a long period. In order to preserve the ingredient of plant body for further longer period, a dehumidifying agent and/or freshnessretaining agent (e.g. silica gel or powder of marble) is preferably put together in the vessel. When a rose flower is put in a 500cc vol. bottle made of a glass and sealed with a lid and kept in a dark place, the flower is can be retained in a fresh state for about 1 month and when silica gel is further together put in the bottle and treated in same way as the above-mentioned way, the flower can be retained in a fresh state for about 1.5 month.