Method and apparatus for producing at least one hollow structure, mirror, EUV lithography system, fluid feed apparatus and method for feeding a fluid

The invention relates to a method for producing a hollow structure (28) in a workpiece (25) in the form of a substrate for a mirror, in particular for an EUV mirror (M4), by way of material-removing processing by means of pulsed laser radiation (35), comprising: radiating the pulsed laser radiation (35) into the workpiece (25) which is formed from a material transparent to the pulsed laser radiation (35) from a radiation entrance side (27), focusing the pulsed laser radiation (35) into a focal region (39), forming a removal front (46) for the areal removal of material of the workpiece (25) by moving the focal region (39) along a movement pattern (41), and producing the hollow structure (28) by moving the removal front (46) within the workpiece (25), wherein a removal front (46) that is not aligned perpendicular to an incoming radiation direction (Z) of the pulsed laser radiation (35) at the radiation entrance side (27) of the workpiece (25) is formed at least intermittently during the production of the hollow