A head positioning method and device positions a head which reads a disk-type storage medium at a specified location, and accurately estimates a bias value during settling control. A disk device includes a disk medium, a head, an actuator, and a control circuit, and settling control is performed based on a detected position after coarse control without integral compensation or bias compensation having been performed. The position of the head for a next sample is estimated, and an initial bias value is estimated from the difference between the detected position and the estimated position. This initial bias value is then used to perform settling control together with integral compensation of bias compensation. Since the accurate initial bias value at the start of settling is estimated, it is possible to reduce the time for correcting the shift in the bias during settling control, and greatly reduce the time required for settling control.