PURPOSE: To improve the working efficiency and operating efficiency of a line by providing a discriminating means to continuously conveyed molding flasks and providing means for storing the acceptance and rejection of the material after pouring and the result of the discrimination of the molding flasks and feeding the corresponding molding flasks to a flask knocking-out device for the accepted or rejected flasks.

CONSTITUTION: The molding flasks 11 are progressively fed on the casting line L and the number group of the lot subjected to pouring in a pouring zone 12 is discriminated by the discriminating means provided to the molding flask 11. The result thereof is stored into a lot storage device 13. The lot groups 1W3...N-1, N inputted to the device 13 subjected to the assessment of the material of the molten cast iron during cooling in the molding flask and the result thereof is inputted to the device 13. The intrinsic number of every lot is read by the molding flask discriminating means in the position of the automatic flask knocking-out device for the accepted flasks and the device 14 is operated when the material of the molten metal is accepted in accordance with the output data from the device 13. The flask is fed to the automatic flask knocking-out device for the rejected flasks when said material is rejected.