Abstract: A method for producing a coated bioactive granule comprising a core granule containing a bioactive substance and a coating film covering the surface of the core, characterized by comprising a step of reducing the concentration of a volatile matters contained in the bioactive substance; and a method for producing the coated bioactive granule wherein the production conditions are controlled in a manner such that physical properties and/or functions of a coated bioactive granule produced (hereinafter referred to as “product data”) meet specifications of physical properties and/or functions of the coated bioactive granule (hereinafter referred to as “product specifications”), based on deviations between product data and product specifications, characterized in that it comprises a step of reducing the concentration of a volatile matters contained in the bioactive substance.