We investigate the cosmological model with the complex scalar self-int
eracting inflaton field non-minimally coupled to gravity. The differen
t geometries of the Euclidean classically forbidden regions are repres
ented. The instanton solutions of the corresponding Euclidean equation
s of motion are found by numerical calculations supplemented by the qu
alitative analysis of Lorentzian and Euclidean trajectories. The appli
cations of these solutions to the no-boundary and tunneling proposals
for the wave function of the Universe are studied. Possible interpreta
tion of obtained results and their connection with inflationary cosmol
ogy is discussed. The restrictions on the possible values of the new q
uasifundamental constant of the theory - non-zero classical charge - a
re obtained. The equations of motion for the generalized cosmological
model with complex scalar held are written down and investigated. The
conditions of the existence of instanton solutions corresponding to pe
rmanent values of an absolute value of scalar field are obtained.