A tablet which comprises solid particles, especially magnesium oxide particles as the main component and has excellent shape retentivity with extremely low susceptibility to wearing and chipping. The tablet has a domed shape on each of the upper and lower horizontal surfaces of a cylindrical plate shape, wherein the domed shape on each of the upper and lower horizontal surfaces satisfies the following requirements (a), (b) and (c) in the cross-sectional shape including the center line of the cylindrical plate shape: (a) each corner has an angle of 25 to 45°, (b) each corner has a horizontal length of 0.30 to 1.0 mm, and (c) the cup has a depth of 0.6 to 1.2 mm.
