Projection lens wavefront manipulator

A projection objective for imaging an in an object plane (OS) of the projection lens arranged pattern has in an image plane of the projection lens by means of electromagnetic radiation of a working wavelength λ <260 nm, a plurality of optical elements having optical surfaces which in a projection beam path between the object plane (OS) and of the image plane are arranged such that a valve disposed in the object plane pattern by means of the optical elements can be imaged in the image plane. Furthermore, a wave front manipulating system for dynamically influencing the wave front of the running from the object plane to the image plane projection radiation is provided. The wavefront manipulation system includes a manipulator that a manipulatable optical element (ME) and an optical element acting on the manipulatable actuator for controllably influencing at least one optical property of the optical element having manipulable. The manipulatable optical element (ME) is arranged the projection lens in the projection beam path between the object plane (OS) and a first lens (L1). Elements of the actuator engage outside of a horizontal projection in the beam path of the optical working areas (UA) of the manipulatable optical element. It is a false light-protection system with at least one protection device for the protection of elements of the actuating device against irradiation of verlaufendem outside the projection ray path stray light is provided. For example, the stray light-protection system can have one or more diaphragms (BL1, BL2).