The characteristics of a hadron gas ionization calorimeter with parall
el-plate electrodes as functions of energy, electric field and pressur
e of the working gas (95%Ar+5%CF4) were investigated. The energy resol
ution of the detector in the range of 30-60 GeV at a pressure of 40 at
m is sigma/E = [(12.0/E)2 + (1.13/square-root E)2)]1/2. The ratio of t
he amplitudes of the signals due to electrons and hadrons is 1.13 +/-
0.03. The duration of the ionization signal is about 40 nsec.