PURPOSE: To prevent apparatus from damage and facilitate maintenance cutting of the cast slab from an operation chamber by carrying a torch truck to a position where the cast piece is to be cut off and pointing the torch to the cast slab by layer operation in case of an accident.

CONSTITUTION: When an accident happens in a multiple strand continuous casting machine, the door of a partition 2 is opened and a torch truck 5 is carried from a standby position S1 to a position S2 where the cast slab is to be cut off. Then, joining operation levers one after another, let the end of the lever project into an operation chamber 3 while supporting the lever with a supporting rod 13. Next, the torch 10 is ignited and a cast slab 9 of the stand that caused trouble is cut off from inside of the operation chamber by turning the operation lever 11 right and left.