[en] The ''Crystal'' installation for studying characteristics of radiation emitted during relativistic electron and positron channeling in monocrystals is described. The main parameters of radiation detectors, gamma spectrometer, recording and control electronic circuits and on-line computer codes are given. An electron (positron) beam is incident on a monocrystal target fixed in a remote-controlled goniometer. A system of drift chambers grouped in three units is used for determining the particle tracks in front of and behind the target. The fourth unit of drift chambers serves for determining the particle tracks behind an analyzing magnet. gamma photons emitted from a target are detected by a scintillation counter on the base of the CsI(Tl) monocrystal surrounded with a lead shield and a system of anti- coincidence counters. Angles of gamma photon emission are measured by means of a drift chamber unit having a built-in converter fixed directly in front of the gamma spectrometer radiator. Cherenkov lead glass shower counters covering the momentum range of 5-10 GeV/c are used for secondary electron (positron) identification. The installation is triggered by a system of coincidence and anticoincidence counters and operates on-line with the ES-1040 computer. The installation recording system is designed in the CAMAC standard. The installation provides resolution by scattering angle equal to about 33 μrad. It is able to detect upto 1400 events per second and involves developed software system