A search for resonant absorption of the solar axion by $^{83}rm{Kr}$ nuclei was performed using the proportional counter installed inside the low-background setup at the Baksan Neutrino Observatory. The obtained model independent upper limit on the c
ombination of isoscalar and isovector axion-nucleon couplings $|g_3-g_0|leq 1.69times 10^{-6}$ allowed us to set the new upper limit on the hadronic axion mass of $m_{A}leq 130$ eV (95% C.L.) with the generally accepted values $S$=0.5 and $z$=0.56.
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 contamina
tion 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.
