A large pressurized gas Čerenkov counter is described. The counter is designed to assist triggering on electrons in high energy counter‐spark chamber experiments. The requirement of large solid angle resulted in a counter of large dimensions and heavy construction. The results of tests made on the counter are presented. The tests indicate that the counter rejects pions very well and is roughly 50% efficient to electrons in the Λ° beta‐decay spectrum (0–200 MeV).