The invention refers to an X-ray beam device for X-ray analytical applications, comprising an X-ray source designed such as to emit a divergent beam of X-rays; and an optical assembly designed such as to focus said beam onto a focal spot, wherein said optical assembly comprises a first reflecting optical element, a monochromator device and a second reflecting optical element sequentially arranged between said source and said focal spot, wherein said first optical element is designed such as to collimate said beam in two dimensions towards said monochromator device, and wherein said second optical element is designed such as to focus the beam coming from said monochromator device in two dimensions onto said focal spot.