A new interpretation of the quantum interference, as a filtering in the pha
se space, is proposed. This filtering is applied to the quantum wavefunctio
n, considered as an amplitude probability distribution, and is due to the m
ismatch of the phase space areas of the quantum system and the experimental
set-up. The quantum particle is considered to have physical reality and is
distinguished from a classical particle through the inherent impossibility
of assigning to it a sharp phase space localizability.