LEMI-046 vector magnetometer is intended for the precise measurement of Earth's magnetic field and its variations at laboratory and land conditions as well as in geomagnetic observatory in Antarctic Region. It means that it is adapted to function in low temperatures. It is produced on the base of flux-gate sensor, all three components of which are implemented in the same body. It consists of two units - sensor unit in waterproof housing and electronic unit mounted in PELI case, both connected by the cable. The electronic unit provides automated operation - acquisition, processing and storage in the embedded SD card of data about magnetic field and its variations and/or their transmission to the external user via RS-232 interface. Built-in GPS receiver assures satellite synchronization of the internal clock and the coordinates of magnetometer location are also registered. It allows organizing the synchronous operation of a set of the magnetometers installed at the studied area. The big enough volume of internal non-volatile memory for data recording and small power consumption allow using this magnetometer for long-term autonomous operation in land conditions.