Аннотация:Based on measurements of H− and H densities a DC glow discharge in H2 (P=0.1-3 Torr) the rate coefficient of H− production as a function of E/N was determined. To analyze the mechanisms of H− production, a simple model of H2 vibrational excitation was developed. Estimations of vibrational level densities (v=3-5) obtained from VUV absorption measurements were in reasonable agreement with the calculated data. The analysis revealed that standard mechanisms of H−production (dissociative attachment to vibrationally excited molecules H2(v) and molecules in Rydberg states H2(\textit{Ry})) were not enough to explain the experimental results. In order to describe both the shape (vs E/N) and the magnitude of the measured H− production rate coefficient, an ``additional'' source of H−, having a strong resonant electron attachment CS in the range of ∼5-9 eV, should be invoked. Although H2 has no resonances in the 5-9 eV range, water is known to strongly dissociatively attach in this range. Thus, even small amounts (0.1-1{\%}) of water vapor in the apparatus can explain the origin of the ``additional'' H− production. This result is corroborated by the work of Cadez \textit{et. al.} in Proc. of XXVII ICPIG, 2005. This work was supported by the RFBR (No.05-02-17649a), Scientific School - 171113.2003.2 and NATO Collaborative Linkage Grant (No.980097).