A revision of the electrostatic gas breakdown wave apparatus used by Haberstich and Winn has been employed to generate waves for studies of wave speed, and electron temperature and density behind the wave front. The measurements were carried out in helium at applied electrode voltages from 6 to 42 kV of both polarities and over a pressure range of 0.3 to 30.0 Torr. Nuclear data‐handling techniques were adapted to the measurement of the wave speeds to increase the accuracy of the data. Good over‐all agreememt is obtained with the theory of Shelton.