  Time analysis of oscillations of a particle between wells in the
one-dimensional double-well potential with infinite high outside walls, based
on wave packet use and energy spectrum analysis, is presented. For the
double-well potential of the form $x^{2}+1/x^{2}$ in the external regions, an
exact analytical solution of the energy spectrum is found (by standard QM
approach), an analysis of oscillation periodicity is fulfilled, an approach for
exact analitical calculation of the oscillation period is proposed (for the
first time for the double-well potential).
