A controlled release microsphere with a coating layer comprising a core containing an exendin as an active ingredient, and a biodegradable polymer, and a coating layer that coats the core with a coating material, in which the biodegradable polymer is a polymer selected from the group consisting of polylactide (PLA), polyglycolide (PGA), poly (lactide-co-glycolide) (PLGA), polyortoester, polyanhydride, polyhydroxybutyric acid, polycaprolactone, and polyalkylcarbonate, a copolymer or a simple mixture of two or more selected from the polymer group； a copolymer of the polymer and polyethylene glycol (PEG), or a polymer-sugar complex in which a sugar is coupled to the polymer or the copolymer, the coating material is one or more selected from the group consisting of basic amino acids, polypeptides, and compounds organic nitrogen, in which the basic amino acid is one or more selected from the group consisting of arginine, lysine, and histidine, the polypeptide comprises from 2 to 10 amino acids in which one or more basic amino acids selected from the group consisting of arginine are comprised , lysine, and histidine, and the number of basic amino acids is greater than that of acidic amino acids, and the organic nitrogen compound is one or more selected from the group consisting of creatine, creatinine, and urea.Una microesfera de liberación controlada con una capa de recubrimiento que comprende un núcleo que contiene una exendina como principio activo, y un polímero biodegradable, y una capa de recubrimiento que recubre el núcleo con un material de recubrimiento, en el que el polímero biodegradable es un polímero seleccionado del grupo constituido por poliláctido (PLA), poliglicólido (PGA), poli(láctido-co-glicólido) (PLGA), poliortoéster, polianhídrido, ácido polihidroxibutírico, policaprolactona, y polialquilcarbonato, un copolímero o una mezcla simple de dos o más seleccionados del grupo polimérico； un copolímero del polímero y polietilenglicol (PEG), o un complejo de
