Abstract: There are provided a novel sintered apatite body and a novel sintered apatite-mineral fiber material composite. The crystals of the sintered apatite have fine dense crystalline structures comprising needle-like fine crystals and are entangled together, whereby the mechanical properties of the sintered apatite body or composite are markedly enhanced. The sintered body and composite wherein the apatite is hydroxyapatite are useful for bioceramic uses. The sintered apatite body or composite is produced by baking an apatite material alone or in contact with a reinforcing mineral fiber material in the presence of water under pressure at a temperature lower than 1000.degree. C., and further at a temperature lower than the temperature causing deterioration of the fiber material in the case of the composite.