An oxide ceramic sintered body of a single component having a purity of at least 99% by weight of titania and a surface with a plurality of pores therein not exceeding 100 pores per square millimeter. The sintered ceramic body is made by preparing a raw titania powder having a purity of at least 99% titania by weight and an average maximum particle diameter of 1 .mu.m, compacting the titania powder to produce a compact, sintering the compact at a temperature in the range of about 1000.degree. C. to about 1300.degree. under ordinary pressure in air, or an inert or reducing atmosphere. The sintered ceramic body may be hot isostatic pressure treated below the sintering temperature in an inert atmosphere under a pressure of at least 500 kg/cm.sup.2 to further reduce the number of pores in the surface. The number of pores in the surface is determined by pressing the sintered ceramic body in sliding contacting engagement with a polishing buff sprinkled with carbon black so that the carbon black is forced into the pores to produce black spots on the surface representing the pores, and thereafter counting the black spots by inspecting the surface under a microscope to determine the number of pores.