Abstract: The present invention relates to a glow-discharge lamp comprising: a chamber body, provided with one or more gas supply and evacuation openings made of insulated material; a gas inner chamber, which expands toward an anode, is bordered on the sides by the inner walls of the chamber body and has a diameter which is largest at approximately the level of the anode and which has its smallest diameter corresponding to the examination sector of the sample to be examined; a sample arranged at the cathode end of the chamber body and with the anode incorporated in the chamber body, whereby the sample preferably is held at zero potential and the anode incorporated in the chamber body and having a passage opening is preferably held at high voltage; an end piece, if necessary, in the form of a window is arranged at the end of the chamber body, wherein at least one window opening (18) is provided in the chamber body (4) at the level of the negative glow light, and the sample (2) seals the inner gas chamber at the cathode