  The results of the experiment searching for 2K-capture with large
low-background proportional counter are presented. The comparison of spectra of
the background of the proportional counter filled with Kr enriched in $^{78}$Kr
(8400 hr) and with natural Kr (3039 hr) is given. A new limit on the half-life
of $^{78}$Kr with regard to 2K-capture, T$_{1/2}\geq2.0\cdot10^{21}$ yrs (95%
C.L.) has been obtained.
