Non-radial oscillations of a non-rotating neutron star are studied. A neutron star is modelled by a spherically symmetric distribution of nuclear matter possessing the properties of an elastic solid bounded by Newtonian gravity. The analytic formalism describing the spheroidal gravitation-elastic vibrations is developed. Emphasis is placed on calculation of the eigenfrequencies of non-radial vibrations. First numerical estimates are presented and compared with those obtained in earlier calculations on the basis of Kelvin's hydrodynamic model.