PURPOSE: To enable the complete utilization of machine output and structurally and functionally simplifying a foundry molding installation.

CONSTITUTION: The upper box OK of the molding box 15 supplied to a first conveying path in a first transfer station 13 is separated from a lower box UK and only the upper box is transferred to a second conveying path 2 having both molding machines 7 and 8 and is supplied to the first molding machine 7. The empty lower box is sent to the second transfer station 14 arranged between both molding machines in the first conveying path 1 and is transferred to an empty space just before the empty upper box coming from the first molding machine 7 in the second conveying path 2. This upper box is moved to the second transfer station at the next sending cycle. The lower box is sent to the second molding machine 8 and is then sent up to a core insertion section. In such a case, the upper box and the lower box are successively moved at the equal feed cycle length corresponding to the molding box dimensions in the conveying direction by using feed cycles offset along both conveying paths.