Provided is a tablet containing the active ingredient of 7-[4-(4-benzo[b]thiophen-4-yl-piperazin-1-yl) butoxy]-1H-quinolin-2-one or a salt thereof, the tablet having excellent disintegration, favourable storage stability, and high light stability in particular, provided is a tablet obtained by coating, with a coating layer containing hypromellose, talc, titanium oxide, and a colorant or the like, a plain tablet which contains 7-[4-(4-benzo[b]thiophen-4-yl-piperazin-1-yl) butoxy]-1H-quinolin-2-one or a salt thereof as an active ingredient, and also contains: lactose, corn starch, crystalline cellulose, or another excipient low-substituted hydroxypropyl cellulose, croscarmellose sodium, sodium carboxymethyl starch, or another disintegrating agent hydroxypropyl cellulose or another binder and stearic acid salt or another lubricant.
