A servo controlling apparatus of a holographic information recording/reproducing system changes the foci of reference light and signal light in a depth direction of a holographic information storage medium to record information over a plurality of information layers. A servo control is changed from a normal servo operation to a between-movement servo operation while movement between information layers is made during a recording operation, and the servo control is changed back to the normal servo operation when the movement between information layers is completed. The between-movement servo operation maintains a servo control state that exists before the movement between information layers.