It is an object of the invention is to provide a light-emitting element in
which failure of the light-emitting element due to separation can be
controlled and stable luminescence can be obtained with high-efficiency
and for a long stretch of time by controlling separation of layers
constituting the light-emitting element. According to one aspect of a
light-emitting element of the invention, the light-emitting element
sandwiches a plurality of layers between a pair of electrodes, wherein at
least one layer of the plurality of layers is a layer containing a
substance selected from bismuth oxide, cobalt oxide, chromium oxide,
copper oxide, nickel oxide, and titanium oxide, or at least one layer of
layers different from a light-emitting layer among the plurality of
layers is a mixed region of one substance selected from bismuth oxide,
cobalt oxide, copper oxide, magnesium oxide, nickel oxide, zinc oxide,
and titanium oxide and an organic compound.