To smoothen a machining route more appropriately. A numerical controller of the present invention comprises: a machining program look-ahead unit that acquires a program for machining; a command route mathematization unit that expresses a machining route as a parametric line segment or curve on the basis of the program for the machining; and a smoothing processing unit that sets a range of smoothing for a target point of the smoothing along the parametric line segment or curve in an optional range from the target point, and performs the smoothing on the target point on the basis of the set range of the smoothing. The range of the smoothing set by the smoothing processing unit is a range in which a deviation between before the smoothing and after the smoothing on the target point is a set threshold or less.