PURPOSE: To process an aggregated material with a large cross-section, then reduce the architectural cost of architecture using the aggregated material, and at the same time, dispense with a processing work at a site.

CONSTITUTION: A cross-cut device 26 is installed which cuts the end part of an aggregated material with a large cross-section deposited on a roller conveyor 25 at right angles. In addition, a horizontal reversing device 28 which reverses the orientation of the aggregated material with a large cross-section is provided on the roller conveyor 25. Further, a hole drilling device 41 is installed which from forms a hole on the side of the aggregated material with a large cross-section with the en cut at right angles. A vertical hole drilling device 51 is also installed which forms a vertical hole in the aggregated material with a large cross-section. An angle reversing device 61 which rotates the aggregated material with a large cross-section to reverse its vertical position is installed on a roller conveyor 56 arranged on the lateral part of the vertical hole drilling device 51. Next, a slitting device 8 which forms a slit on both sides of the aggregated material with a large cross-section deposited on a roller conveyor 72 after the completion of the hole drilling work is installed with the installation of a horizontal reversing device 28 for changing the orientation of the aggregated material on the conveyor 72.