Disclosed is a tablet which can sustain excellent disintegration properties (hereinafter sometimes referred to as "quick disintegration properties"), as a tabletted product, over a long time and has a high shape-retention stability caused by an improvement in the tablet strength.An antacid and laxative tablet comprising magnesium oxide particles as the main ingredient, characterized by: (a) the magnesium oxide particles contained in the tablet having an average secondary particle diameter, measured by the laser diffractive scattering method, of 0.5-10 μm； (b) the amount of the magnesium oxide particles contained therein being 85-96 wt%； (c) the amount of crystalline cellulose contained therein as a binder being 2-8 wt%； (d) the amount of croscarmellose sodium contained therein as disintegrating agent-I being 0.8-2.5 wt%； (e) the amount of insoluble polyvinylpyrrolidone contained therein as disintegrating agent-II being 1-3.5 wt%； and (f) the amount of a lubricant contained therein being of 0.5-2 wt%.
