  The physical properties of bound-state charged massive scalar field
configurations linearly coupled to a spherically symmetric charged reflecting
shell are studied {\it analytically}. To that end, we solve the Klein-Gordon
wave equation for a static scalar field of proper mass $\mu$, charge coupling
constant $q$, and spherical harmonic index $l$ in the background of a charged
shell of radius $R$ and electric charge $Q$. It is proved that the
dimensionless inequality $\mu R<\sqrt{(qQ)^2-(l+1/2)^2}$ provides an upper
bound on the regime of existence of the composed
charged-spherical-shell-charged-massive-scalar-field configurations.
Interestingly, we explicitly show that the {\it discrete} spectrum of shell
radii $\{R_n(\mu,qQ,l)\}_{n=0}^{n=\infty}$ which can support the static
bound-state charged massive scalar field configurations can be determined
analytically. We confirm our analytical results by numerical computations.
