End-group components for superconducting accelerator cavity used in acceleration of charged particles are manufactured by subjecting pure niobium sheet materials to press forming composed mainly of flat-bottomed cylindrical drawing, preferably by simultaneously conducting control of slide velocity and/or its motion and control of tool die temperature and/or its distribution/gradient in the above press forming, further preferably by dynamically controlling blank holding force in accordance with the variation of flange area, flange thickness and deformed characteristics of niobium sheet materials during the press forming, more preferably by preparing an anisotropically shaped blank instead of a circular blank by use of servo press forming machine, servo-die cushion temperature control equipment, water-soluble solid coating type lubricant, and a tooling die.