  We report a new measurement of the neutron lifetime using ultra-cold neutrons
stored in a magneto-gravitational trap made of permanent magnets. Neutrons
surviving in the trap after fixed storage times have been counted and the trap
losses have continuously been monitored during storage by detecting neutrons
leaking from the trap. The value of the neutron lifetime resulting from this
measurement is $\tau_n=(878.3\pm1.9)$s. It is the most precise measurement of
the neutron lifetime obtained with magnetically stored neutrons.
