PURPOSE: To produce a billet utilized to rolling base stock, base material for remelting, etc., in good productivity.

CONSTITUTION: On the inner peripheral surface 2a of a cylindrical mold 2, plural grooves shaped casting spaces 3 opened on the inner peripheral surface 2a of the mold and extended in the parallel direction with the cylindrical axial direction, are formed in the fixed intervals in the circular circumference. While rotating the cylindrical mold 2 in the circular circumferential direction, molten metal 20 is poured into plural groove-shaped casting spaces 3 and is solidified in the state of holding the molten metal 20 in the groove-shaped casting space 3 by centrifugal force to form the billet in each groove-shaped casting space 3.