PURPOSE: To effectively demolishing an upper part of a structure by obtaining block type demolished pieces by way of cutting demolition parts into blocks while supporting the parts from below by a lift table provided on a carriage, and carrying out the demolished pieces on the carriage as they are.

CONSTITUTION: A carriage 10 is positioned and stopped under a ceiling part of a tunnel or others to demolish and installed by actuating an outrigger 14. Then, a lift system 20 is actuated and a lift table 11 is lifted up, and the lift table 11 is pressed on the lower surface of a part to be demolished. Thereafter, the ceiling part is cut into blocks by a wire saw, and demolition pieces 30 cut into blocks is supported by the lift table 11. Thereafter, the lift system 20 is actuated and the lift table 11 is lifted down and placed on the carriage 10, and the outrigger 14 is actuated and the fixed state of the carriage 10 is cancelled. Furthermore, the carriage 10 is moved along a track 5 to carry, demolition pieces 30.