A cylindrical plasma column was produced in hydrogen by a microwave electric field crossed with a static magnetic field. Under certain conditions of gas pressure, magnetic field, and strength of the microwave field, the plasma did not entirely fill the volume available to it but appeared as a narrow, perfectly stable, cylindrical column with a diameter as small as one‐fourth of the diameter of the discharge tube. The experimentally observed properties of this ``constricted'' discharge are described. It is shown that they can be explained by treating the plasma as a compressible dielectric medium.