PURPOSE: To improve feeder head effect by restraining the temp. drop of molten steel in a feeder head and also, to reduce gas quantity produced by combustion of a foam resin.

CONSTITUTION: A lost foam pattern 1 covering bottomed cylindrical bodies 2 having fine gas venting holes at the tip part of feeder head pattern parts 1d is buried into the molding sand 5 fitted up in a molding flask 4. The feeder head part is formed of the feeder head pattern part 1d and the cylindrical space 1e. The gas produced by the combustion of the lost foam pattern 1 is exhausted into the molding sand 5 through the gas venting holes of the bottomed cylindrical bodies 2.