To provide a naturally decomposable urn which enables the returning thereof back to soil with ashes of dead persons by accomplishing natural decomposition thereof by the biodegradation thereof with mocroorganisms in the soil and the weathering thereof due to climatic changes spending fixed years without requiring the discarding of the urn while securing a specified heat resistance, and a production method thereof.

Either of gypsum or clay, or both are mixed with starch at a proper rate to be formed as a main component. One or two or more of biodegradable materials and (or) inorganic materials in the form of powder, particles, a mass or pellets are added to the main component and mixed together. A glue solution is added to the mixture to be knead and then, the mixture is poured to fill a specified mold. The work thus obtained is dried at a normal temperature to make an urn with a specified shape.