1. A biological sample image acquiring apparatus comprising: an objective lens magnifying a region of a biological sample; an imaging device imaging the region magnified by the objective lens; a movement controller moving the focus of the objective lens in the thickness direction of the target region of the biological sample and moving the image of the region, which is magnified by the objective lens to be imaged onto the imaging device, in an in-plane direction; and a biological sample image acquiring unit acquiring a biological sample image of the region by exposing the imaging device to light while the movement controller is moving the image of the region, wherein the movement controller moves at least one of the focus of the objective lens and the image of the region separate from any movement of the biological sample according to a programmed routine, and wherein the imaging device is configured to image the region of the biological sample while the movement controller concurrently moves i) the focus of the objective lens in the thickness direction from a cover glass side to a slide glass side of the biological sample regardless of any focusing of the biological sample and ii) the image of the region in the in-plane direction.