A Townsend-type discharge generated in a modified ionization cell with symmetrical short gaps between a high-resistivity semiconductor plate and two planar electrodes is studied. The spatial stabilization of the gas discharge cell with a planar GaAs semiconductor plate is studied over a wide range of gas pressure values 101-342 Torr. The characteristics of the system are obtained both without and with illumination of the semiconductor plate with light of a particular wavelength range to control the photoconductivity of the material. The semiconductor material is found to stabilize the discharge. It is shown that generation of carriers by a gas discharge establishes a positive feedback. A qualitative discussion of this effect is given, which includes avalanche formation in a system having high-resistivity semiconductor for the Townsend discharge region. Recording of the current-voltage characteristic between parallel-plane electrodes is realized.