A numerical controller that controls a machine based on a program, the machine including a drive unit that is driven by at least one or more ball screws, includes: instruction program analyzing unit for analyzing the program and generating movement instruction data based on an analysis result; and speed changing unit for evaluating a safe feed speed at a position that is indicated by a coordinate value of the drive unit, based on the coordinate value, and restricting a movement speed of the drive unit up to the safe feed speed, the movement speed of the drive unit being included in the movement instruction data.