PURPOSE: To facilitate the production of a seal by casting a sealing surface from titanium or a titanium alloy.

CONSTITUTION: The sealing surface 1a of a seal 1 made of titanium or a titanium alloy is produced by a precise casting device 31. In the precise casting device 31, a melting means melting a metal matrix 37 composed of titanium or a titanium alloy is constituted of a water cooled magnetic concn. body 18 made of copper and a high frequency heating coil 36. The metal matrix 37 is supplied to the inside of the magnetic concn. body 18 from below. The molten metal 47 of titanium or a titanium alloy is formed by the melting means and evacuated in the direction shown by an arrow P through the vacuum suction pipe 46 provided to a vertical sleeve 35. By this method, a casting chamber 39 is reduced in pressure to reduce the pressure in the casting space 33a of a ceramic shell casting mold 33 having air permeability and the molten metal 47 is sucked to be cast. At this time, induction heating is continued for several sec after the completion of suction to prevent the coagulation of the molten metal 47 in a hollow pipe 42 to push the molten metal 47.