Abstract: A space defined by inside surfaces of a main molding flask and lower auxiliary flask and the upper surface of a pattern plate where the upper surface of the pattern plate is retained at a predetermined level along the inside surfaces of the main molding flask and lower auxiliary flask is filled with an amount of molding sand. The molding sand is then squeezed in the space with upper and lower press heads in at least one of upward and downward directions to form at least one of first and second halves of a sand mold such that a lower surface of the first or second half of the sand mold is formed at a desired level along the inside surfaces of the main molding flask and lower auxiliary flask irrespective of edges of the main molding and lower auxiliary flasks. The desired level is determined by the level of the upper surface of the pattern plate at the time when the squeezing step has finished.