  We study the quantum behaviour of Reissner-Nordstr\"om (RN) black-holes
interacting with a complex scalar field. A Maxwell field is also present. Our
analysis is based on M. Pollock's method and is characterized by solving a
Wheeler-DeWitt equation in the proximity of an apparent horizon of the RN
space-time. Subsequently, we obtain a wave-function $\Psi_{RN}[M, Q]$
representing the RN black-hole when its charge, $\mid Q \mid$, is small in
comparison with its mass, $M$. We then compare quantum-mechanically the cases
of $(i)$ $Q = 0$ and $(ii)$ $M \geq \mid Q \mid \neq 0 $. A special emphasis is
given to the evolution of the mass-charge rate affected by Hawking radiation.
