[OBJECT] To provide an intraorally rapidly disintegrating tablet comprising 2-(3-cyano-4-isobutyloxyphenyl)-4-methyl-5-thiazolecarboxylic acid as an active ingredient, which is a formulation that causes virtually no irritating sensation in the oral cavity or pharynx, and retains good dissolution and oral disintegration properties even when it is stored under high temperature/high humidity conditions.[MEANS OF REALIZING THE OBJECT] An intraorally rapidly disintegrating tablet comprising a particle containing a 2-(3-cyano-4-isobutyloxyphenyl)-4-methyl-5-thiazolecarboxylic acid-containing core particle coated with a layer comprising a methacrylic acid copolymer and further overcoated with a layer containing a water-soluble saccharide.