The present invention relates to a method of manufacturing a window transparent for electrons of an electron beam (E), in particular of an X-ray source. In order to enable a less costly and elaborate manufacture of such a window and in order to prevent unwanted sharp edges in a window area which may damage the window foil (2), a method is proposed comprising the steps of:—providing on a surface (11) of a carrier element (1) to which a window foil (2) shall be a fixed a receiving area (13, 16) for receiving a soldering material (3) used for fixing said window foil (2) to said carrier element (1), said carrier element (1) comprising a through hole (12) for the transmission of said electrons (E),—covering said surface (11) having said receiving area (13, 16) with a soldering material (3) such that substantially only said receiving area (13, 16) is filled with soldering material (3),—placing said window foil (2) on top of said surface (1) and—heating said soldering material (3) for fixing said window foil (2) to said surface (11).