  Quantum origin of the early inflationary Universe from the no-boundary and
tunnelling quantum states is considered in the one-loop approximation of
quantum cosmology. A universal effective action algorithm for the distribution
function of chaotic inflationary cosmologies is derived for both of these
states.The energy scale of inflation is calculated by finding a sharp
probability peak in this distribution function for a tunnelling model driven by
the inflaton field with large negative constant $\xi$ of nonminimal
interaction. The sub-Planckian parameters of this peak (the mean value of the
corresponding Hubble constant ${\mbox{\boldmath $H$}}\simeq 10^{-5}m_P$, its
quantum width $\Delta{\mbox{\boldmath $H$}}/{\mbox{\boldmath $H$}}\simeq
10^{-5}$ and the number of inflationary e-foldings ${\mbox{\boldmath
$N$}}\simeq 60$) are found to be in good correspondence with the observational
status of inflation theory, provided the coupling constants of the theory are
constrained by a condition which is likely to be enforced by the (quasi)
supersymmetric nature of the sub-Planckian particle physics model.
