Abstract: A numerical control device according to the present invention progressively analyzes a machining program stored in a storage device by one program block or by a plurality of program blocks, computes a migration rate and a feed speed in each axial direction from an instructed moving position of a tool and a feed speed of the tool in an interpolating section, outputs a positional instruction to an object for control for each given cycle, and has a sampling time interval computing section for computing a sampling time so that a number of instruction pulses for each sampling time under a given feed speed is kept at a constant value when a migration rate for 1 block computed in the interpolating section is divided to a number of pulses for each sampling time, and an interruption controlling section for setting a variable sampling time.