To attain high resolution by employing a positional signal outputted from a linear scale, i.e., pulses of phases A and B, as a positional feedback amount and employing a speed data calculated through an interpolation/data generating means as a speed feedback amount for speed control.

A command voltage is applied through a position control means 11, a speed control means 12 and a current control means 13 to a linear motor 6 which is thereby driven and the shifted position thereof is detected by means of a linear scale 1. A position feedback amount for positional control employs a positional signal outputted from the linear scale 1, i.e., pulses of A, B pulses, whereas a speed feedback amount for speed control employs a data obtained by interpolating an analog sine and cosine signals outputted from the linear scale 1 through an interpolation/data generating means 14. Since positional resolution is not limited, speed and acceleration components can be detected with high resolution and a servo system excellent in response can be configured.