Germanium, a metallic chemical element. It is brittle, lustrous, and silver-gray at ordinary temperatures. Germanium is a semiconductor and is used in making some transistors and other electronic devices. Glass containing germanium is used in equipment designed to transmit, detect, or study infrared radiation. The metal occurs in the ores of such metals as zinc and copper and in certain kinds of coal.

Germanium was isolated in 1886 by Clemens A. Winkler, who named the element after his native Germany. Commercial production did not begin until 1942.