To obtain a sintered compact which has high, uniform density, and also has reduced voids.

The method of producing the sintered compact includes a stage 10 where a first raw material and a second raw material are mixed and reacted, so that slurry containing the resultant synthesis is obtained; a stage 20 where the slurry is concentrated; a stage 30 where gas is removed from the slurry; a stage 40 where the slurry is filled into a compacting die, and is dried to obtain a temporary compact; a stage 50 where the temporary compact is compressed to obtain a compact; a stage 60 where the compact is subjected machining; and a stage 70 where the compact is sintered to obtain a sintered compact. At least either the first raw material or second raw material is preferably used as a solution, and the stage 50 where the compact is obtained is performed preferably in an evacuated state. Further, as the synthesis, a ceramic material, particularly, a calcium phosphate based compound in which the ratio of Ca/P is 1 to 2 such as hydroxyapatite and tricalcium phosphate is preferable.