We investigate the electronic structure of a many-electron spherical quantum dot with and without hydrogenic impurity. The number of electrons is taken as N=18. The density functional theory is used within local density approximation. Total energy, chemical potential, addition energy spectra, and the shell structure are determined and the results obtained are compared for cases with and without impurity. It is observed that the capacitive energy with the impurity increases in the 1s shell with respect to the case without the impurity.