It is an object of the present invention to provide a fine core particle, which comprises a coating layer having a uniform thickness, and which can be used to produce, at a high yield, a small granule causing no sandy feeling in the oral cavity when the fine core particle is applied to a fine granule or an orally-disintegrating tablet. According to the present invention, there is provided a core particle, which comprises 50% by mass or more of microcrystalline cellulose, and which has a mean particle diameter of less than 100 µm, a relative flow index of 7.0 to 30.0, a specific surface area of less than 0.15 m2/g, and a tapped bulk density of 0.80 g/mL or more.