Details are given of a Littrow‐mounted grating spectrometer which uses a cooled linear array of silicon diodes as a detector (0.4–1.1 &mgr;) and an Erfle eyepiece as collimator/camera. The slit is illuminated by a standard 35 mm camera lens. Analog diode output signals are multiplexed, digitized, and either recorded on magnetic tape for later processing or signal‐averaged by a small on‐line computer, then recorded on magnetic tape, and displayed on an oscilloscope. Test data are presented. The device has no moving parts, is competitive with existing devices based on photomultipliers and television cameras, and can be readily modified to increase the number of channels and improve wavelength and spatial resolution and throughput.