Abstract: Contact materials for vacuum switches with the base constituents copper and chromium and additive constituents containing tellurium or selenium and in which copper-telluride (Cu.sub.2 Te) or copper-selenide (Cu.sub.2 Se) are formed as a binary intermetallic phase are known. According to the invention, the additive constituent is a ternary intermetallic phase composed of copper, chromium and tellurium or copper, chromium and selenium with a tellurium or selenium content which is greater than that of the known binary intermetallic phases. This results in a reduction of the chopping currents in the contact pieces manufactured from the contact material according to the invention and causes the overvoltage performance to be enhanced.