PURPOSE: To make accurate measurement of a machining time at each machining process even when a work is machined at a plurality of processes.

CONSTITUTION: In a first processing part 1, an NC program is called from an NC program memory part by a first processing device 3 based on machining information inputted from an input part 4 and a work is machined by executing the NC program. In a second processing part, a machining time at each process is measured by given symbol and numeral described at the NC program by a second processing device 6 based on an input signal from the first processing part 1 simultaneously with execution of the NC program by a process time counting part 9. A machining time measured by a display means 7 is displayed together with each machining process.