To easily mark a guide passage of a puncture needle by providing an optical system to radiate a light beam, and arranging this optical system so as to be freely movable and rotatable along a rail in a device to mark a prescribed guide passage of an apparatus in a medical inspection device.

A rail 3 to guide an optical system 4, for example, a light source of a laser beam is arranged in a CTI having a table 2 on which a patient is placed, and the optical system 4 is installed so as to be freely movable and freely rotatable along this rail 3. In the case of marking, a piercing point and a target point are set on a planning drawing in a computer 6, and an angle of a straight line connecting two points and a perpendicular is found, and the optical system 4 is automatically positioned according to its result, and a laser beam is irradiated. When a puncture needle is inserted, the needle is placed at a piercing point, and an angle is changed until a light beam 5 is discriminated in an upper end part of the needle. Next, it is inserted by a length quantity measured by the planning drawing, and a needle position is controlled by another CT image.