Abstract
The energy spectrum of the quantum elliptic billiard is obtained by solving the Schrodinger equation in elliptic coordinates. The corresponding eigenstates also diagonalise an operator B which commutes with H. A numerical search of the exact eigenvalues of B and H permits one to follow each state as a function of the deformation parameter mu . Geometrical arguments, also valid for the simpler problem of the rectangular box, allow one to understand the results obtained.