To provide a release sheet which has elasticity coping with the expansion or contraction of an adhesive film, has strength enduring a load brought about by delaminating the adhesive film, and has biodegradability enabling to be disposed.

The biodegradable release sheet comprises a mixture of starch and an organic substance as the main raw materials which are each a biodegradable resin material and a natural fiber materials as a highly strengthening additive mixed to the main raw materials.