Abstract: A device for attraction holding a measurement object in an interferometer comprises a holding surface having holes and an air chamber communicating with the holes through suction passages formed between the holding surface and air chamber so as to attract and hold an object on the holding surface by exhausting the air from the air chamber. The air chamber is sealed by at least one flexible member which is deformed when an excessive negative pressure is established in the air chamber, so as to prevent distort or deformation of the holding surface, and hence the object held thereon.

Abstract: A device for holding a measurement object e.g. in interferometers comprises a base plate and an attraction plate mounted on the base plate so as to attract the object placed on an upper surface of the attraction plate to the base plate together with the attraction plate by a vacuum applied via attraction grooves formed on the base plate and attraction passages perforated through the attraction plate. The upper surface of the base plate is formed as a reflection plane, and the attraction plate is made of a transparent material, so that Newton's rings generated by light reflected from the upper surface of the base plate and light reflected from the lower surface of the attraction plate can be observed from above the attraction plate.