Disclosed are: a process for producing spherical microparticles comprising tamsulosin hydrochloride； spherical microparticles produced by the process； coated microparticles produced by coating the spherical microparticles； and an orally disintegrating tablet comprising the coated microparticles. The process comprises the following steps (1) to (3): (1) mixing/stirring tamsulosin hydrochloride (a), microcrystalline cellulose (b) and water together until water is penetrated into the mixture of the components (a) and (b) homogeneously； (2) granulating the mixture produced in step (1) into granules by using a rotating granulator in which the peripheral speed is set to 5.5 to 9.0 m/s； and (3) drying the granules produced in step (2).
