  The present paper is based upon equations obtained in an earlier paper by the
author devoted to a new formulation of quantum electrodynamics. The equations
describe the structure of the electron as well as its motion in external
fields, interaction with a measuring apparatus inclusive, in a deterministic
manner without any jumps. Quantum mechanics is an approximate theory because
its equations follow from the above equations upon neglecting the self-field of
the electron itself. Just this leads to paradoxes, seeming contradictions and
jumps in quantum mechanics. The quantum mechanical wavefunction has a dual
interpretation. In some problems the square of its modulus represents a real
distribution of the electronic density while in others the same square
determines the probability distribution of coordinates. It is shown why, given
the different interpretations of the wavefunction, it satisfies one and the
same Dirac or Schr\"odinger equation. Description of many-electron systems is
also considered in the starting approach as well as in quantum mechanics.
Neutrinos are discussed in brief.
