To enhance the life of the saw blade of a sawing machine by inhibiting lancing before the saw blade wears out.

Material and dimension are inputted from the input device 7 of a controller 3 to a computing part 13 and cutting work is started. As the cutting work proceeds, the cumulative cutting area of a saw blade BS is calculated by the computing part 13 and a set cut area corresponding to a limit value of lancing is retrieved from a database comprising materials and dimensions which are inputted into a memory 15. A comparison judging device 17 compares the cumulative cutting area with the set cutting area and, when the cumulative cutting area of the saw blade BS exceeds the set cutting area, the cutting speed of the saw blade BS and/or the speed of the saw blade BS is decreased and the cutting work is continued. Since correction allowing for the cumulative cutting area of the saw blade BS is effected before the saw blade BS wears out, quality is further enhanced and the life of the saw blade BS is extended.