  We present the first CCD flux-calibrated images of the snr G 82.2+5.3 in
major optical emission lines. The [O III] 5007 line provides the first direct
evidence of optical emission originating from G 82.2+5.3. Filamentary emission
is detected in the west and east areas, roughly defining an ellipsoidal shell.
The [O III] emission is rather well correlated with the radio emission
suggesting their association, while typical fluxes are found in the range of
20-30x10^{-17} erg s^{-1} cm^{-2} arcsec^{-2}. Deep long-slit spectra taken at
specific positions of the remnant verify that the filamentary emission
originates from shock heated gas with shock velocities ~100 km/s and low
electron densities, while the diffuse [O III] emission in the south results
from photoionization processes. The X-ray surface brightness is quite patchy,
missing obvious limb brightening and is dominated by a bright bar-like emission
region which is off-set from the geometric center by ~9'. The X-ray emission is
thermal and requires two temperatures of 0.2 keV and 0.63 keV. The bright bar
region shows overabundant Mg, Si and Fe, which might indicate still radiating
ejecta matter. The azimuthally averaged radial surface profile is consistent
with the matter density changing with distance r from the center ~e^{-r/r_0}
with a characteristic angular length of 36', or, alternatively, with an
r^{-1/2} density profile. The matter inside the remnant is quite likely
structured like a porous cloudy medium. The average matter density is ~0.04 x
d_{1.6}^{-0.5}. Because of the low density and the long cooling times involved
the remnant is more likely to be in the adiabatic phase, which is consistent
with the densities derived for the X-ray plasma and the optical line emission,
but it is not excluded that is has reached the radiating phase.
