| 摘要 |
The present invention relates to a projection exposure apparatus for microlithography, in particular EUV projection exposure apparatus, having a beam path along which propagates electromagnetic radiation with which the projection exposure apparatus is operated, and having at least one filter (55) arranged in the beam path, wherein the projection exposure apparatus furthermore comprises at least one sensor device for monitoring the filter, wherein at least one blocking element (60) is provided which is movable between a standby position and a barrier position, and wherein the movement of the blocking element can be effected at least in a manner dependent on a signal of the sensor device. The invention furthermore relates to a method for operating an apparatus of this type. |
