Lithographic apparatus

A device manufacturing method, comprising:

• providing a substrate that is at least partially covered by a layer of radiation-sensitive material;
• conditioning a beam of radiation using an illumination system;
• providing a support configured to support a patterning device;
• configuring the beam of radiation with a desired pattern in its cross-section based on the patterning device;
• projecting the patterned beam of radiation onto a target area of the layer of radiation-sensitive material;
• and
• selectively obstructing a portion of the patterned beam via a spatial filter, said selectively obstructing a portion of the patterned beam including:
• employing a first and a second pair of spatial filtering structures disposed in a path of the patterned beam of radiation;
• positioning the first pair of spatial filtering structures at a predetermined distance from each other in a direction;
• positioning the second pair of spatial filtering structures at a predetermined distance from each other in the same direction, and
• moving the second pair of spatial filtering structures with respect to the first pair of spatial filtering structures in order to cause the patterned beam to scan along the same direction.