A method of producing a sintered article of polybenzimidazole by using a polybenzimidazole resin is disclosed. This method comprises the steps of: filling a mold with a polybenzimidazole resin; after closing the mold so that the polybenzimidazole resin can be densely packed in the mold, heating the mold to a predetermined temperature ranging from 500.degree. C. to 600.degree. C. without applying pressure to the mold from the outside; after increasing the pressure on the mold from 0 kg/cm.sup.2 to 50-750 kg/cm.sup.2, sintering the polybenzimidazole resin while maintaining the temperature and the pressure for 15 to 200 minutes; cooling the mold; and removing the sintered article of the polybenzimidazole resin from the mold. By this method, sintered articles of polybenzimidazole resins having no weak parts can be obtained in high yields.