The present invention relates to an apparatus (10) as well as a method for generating X-ray radiation, in particular for generating an X-ray radiation field, comprising an electron source (11) for generating an electron beam (12) as well as a target (13) for generation of X-ray radiation, in particular of an X-ray radiation field by electrons of the electron beam (12) impinging on the target (13). The present invention is characterized in that, the apparatus (10) is designed for generating an adjustable and/or changeable X-ray radiation, in particular for generating an adjustable and/or changeable X-ray radiation field, and in that the apparatus (10) has a variation appliance (15) for varying of at least one parameter of the electron beam source (11) and/or the electron beam (12) for influencing the X-ray radiation, in particular the X-ray radiation field.