To provide a high speed servo controller capable of performing a high speed and high performance control beyond control performance by 2 degree of freedom PID control.

The controller calculates control deviation by subtracting an actual control result yk from a target instruction rk by a subtractor 12, and operates a following control arithmetic operation to the control deflection by a feedback(FB) control arithmetic part 16. A feed/forward(FF) control.arithmetic part 14 operates the control arithmetic operation of fbk=(K2+K3Z-1+K4 Z-2)(rk-yk)/(1-Z-1)(1-K1Z-1), ffk=(K5+K6Z-1)rk/(1-K1Z-1), and uk=fbk+ffk based on the target instruction. The feedback arithmetic result fbk of an FB control arithmetic part 16 is added to the feedforward arithmetic result ffk of an FF control arithmetic part 14 by an adding circuit 18, and a motor 1 is driven. In this formula, K1-KN is a gain, rk is a target instruction in a sampling cycle (k), yk is an actual value, fbk is a feedback arithmetic result, ffk is a feedforward arithmetic result, and uk is a control signal.