Abstract: A miniaturized inert gas ion laser is proposed whose discharge column has a diameter between 6.times.10.sup.-3 cm and 8.times.10.sup.-2 cm. In a preferred embodiment, a BeO plate is enclosed by two metal parts which lie against one of the base areas of the plate. One metal part is a copper sheet functioning as anode and the other metal part forms a cavity in which the cathode is situated. The BeO plate is provided with a longitudinal bore which is terminated at both sides by mirrors and communicates via plate perforations with the anode and the cathode space. The bore is 0.1 mm in size and 30 mm long; the discharge occurs on a path of 10 mm; discharge current, discharge voltage and filling pressure lie at 200 mA, 130 V and 5 Torr; the output power amounts to about 1 mW. This type of laser is extremely compact; it is particularly suitable as a stable frequency signal generator and can be simply amplitude-modulated and/or frequency-modulated.