  We report the discovery of a candidate X-ray supernova remnant SRGe
J003602.3+605421=G121.1-1.9 in the course of \textit{SRG}/eROSITA all-sky
survey. The object is located at (l,b)=(121.1$^\circ$,-1.9$^\circ$), is
$\approx36$ arcmin in angular size and has a nearly circular shape. Clear
variations in spectral shape of the X-ray emission across the object are
detected, with the emission from the inner (within 9') and outer (9'-18') parts
dominated by iron and oxygen/neon lines, respectively. The non-equilibrium
plasma emission model is capable of describing the spectrum of the outer part
with the initial gas temperature 0.1 keV, final temperature 0.5 keV and the
ionization age $\sim 2\times10^{10}$ cm$^{-3}$ s. The observed spectrum of the
inner region is more complicated (plausibly due to the contribution of the
outer shell) and requires substantial overabundance of iron for all models we
have tried. The derived X-ray absorption equals to $(4-6)\times10^{21}$
cm$^{-2}$, locating the object at the distance beyond 1.5 kpc, and implying its
age $\sim(5-30)\times1000$ yrs. No bright radio, infrared, H$_\alpha$ or
gamma-ray counterpart of this object have been found in the publicly-available
archival data. A model invoking a canonical $10^{51}$ erg explosion (either SN
Ia or core collapse) in the hot and tenuous medium in the outer region of the
Galaxy $\sim$9 kpc away might explain the bulk of the observed features. This
scenario can be tested with future deep X-ray and radio observations.
