  A concise technical characteristic of a new low-background laboratory
DULB-4900 of the BNO INR RAS is presented. The technique and the results of
background measurements in the Hall, ordinary box and low-background box are
presented. Rn-222 contamination in the laboratory air has been measured by
direct detection of gamma-radiation of its daughter Bi-214 distributed over the
volume of the low-background box. The results of the data analysis are
presented.
