  We investigated Ce-substitution and reduction annealing effects on the
electronic states at copper sites by Cu ${K}$-edge x-ray absorption near-edge
structure measurements in Pr$_{2-x}$Ce$_x$CuO$_{4+\alpha-\delta}$ (PCCO) with
varying $x$ and $\delta$ (the amount of oxygen loss during annealing) values.
Absorption near-edge spectra were modified by Ce-substitution and reduction
annealing in a similar manner with increasing $x$ and $\delta$. Considering
electron doping by Ce-substitution, this similarity indicates an increase of
electron number at the copper sites due to annealing $n_{\rm AN}$. Thus, the
total number of electrons is determined by the amount of Ce and oxygen ions.
Furthermore, quantitative analyses of the spectra clarified that the number of
Cu$^+$ sites, corresponding to the induced electron number by Ce-substitution
$n_{\rm Ce}$ increases linearly with $x$ in the as-sintered PCCO ($\delta=0$),
whereas $n_{\rm AN}$ is not exactly equal to twice of $\delta$, which is
expected from charge neutrality. For each $x$-fixed sample, $n_{\rm AN}$ tends
to exceed 2$\delta$ with increasing $\delta$, suggesting the emergence of two
types of carrier due to annealing.
