A head position control device uses a current observer control which performs two degree of freedom control, with which a current step difference due to the difference of eccentricities between heads is prevented without affecting the seek waveform after switching heads. The head position control device has a locus generation section, which calculates an initial value of the correction locus for canceling the current step difference of the output current based on an output current supplied to an actuator before switching, and an eccentricity correction current and initial velocity of another head after switching; and a two degree of freedom control system to which a seek locus is input, and supplies a correction locus according to the initial value to the two degree of freedom control system. One parameter can correct the initial velocity and the current step difference.