  The NEMO 3 detector, which has been operating in the Frejus underground
laboratory since February 2003, is devoted to the search for neutrinoless
double beta decay (bb0nu). Half-lives of the two neutrino double beta decays
(bb2nu) have been measured for 100Mo and 82Se. After 389 effective days of data
collection from February 2003 until September 2004 (Phase I), no evidence for
neutrinoless double beta decay was found from ~7kg of 100Mo and ~1 kg of 82Se.
The corresponding lower limits for the half-lives are 4.6 x 10^23 years for
100Mo and 1.0 x10^23 years for 82Se (90% C.L.). Depending on the nuclear matrix
elements calculation, limits for the effective Majorana neutrino mass are <m> <
0.7-2.8 eV for 100Mo and <m> < 1.7-4.9 eV for 82Se
