A tablet which can sustain excellent disintegration properties (may be referred to as "quick disintegration properties" hereinafter), as a tableted product, for a long time and has excellent shape-retention stability by the improvement of the strength of the tablet. The antacid and laxative tablet comprises magnesium oxide particles as the main component, wherein (a) the average secondary particle diameter measured by a laser diffraction scattering method of the magnesium oxide particles is 0.5 to 10 µm, (b) the content of the magnesium oxide particles is 85 to 96 wt%, (c) the content of crystalline cellulose as a binder is 2 to 8 wt%, (d) the content of croscarmellose sodium as a disintegrating agent-I is 0.8 to 2.5 wt%, (e) the content of insoluble polyvinyl pyrrolidone as a disintegrating agent-II is 1 to 3.5 wt%, and (f) the content of a lubricant is 0.5 to 2 wt%.
