A focus search control unit for outputting an order to move an objective lens to the vicinity of a targeted position is provided with a trajectory generating unit for generating a position trajectory to move the objective lens such that the objective lens approaches the targeted position gradually. The position trajectory output from the trajectory generating unit is a position trajectory with which resonance frequency components that the lens moving unit has are removed or attenuated by making smooth the variation of acceleration of the objective lens moved by the lens moving unit. The position trajectory is defined by, for example, a function of third order or higher with respect to time.