When a numerical controller executes a tool-center-point control in which a path of a tool center point with respect to a workpiece is instructed, and the workpiece is machined along the instructed path based on a speed instruction, the numerical controller sets the speed instruction so that the speed instruction is a synthesis speed with respect to a synthesis distance of a relative moving distance between the workpiece and a tool center point and a tool-direction changing distance due to a relative change in a tool direction with respect to the workpiece by a rotary axis. The numerical controller interpolates a position of a linear axis and a position of a rotary axis by the tool-center-point control according to the synthesis speed and drives the linear axis and the rotary axis to the position of the linear axis and the position of the rotary axis created by the interpolation.