  We present the results of high-resolution optical spectroscopy,
low-resolution near-IR spectroscopy and near-infrared speckle interferometry of
the massive young stellar object candidate V645 Cyg, acquired to refine its
fundamental parameters and the properties of its circumstellar envelope.
Speckle interferometry in the $H$- and $K$-bands and an optical spectrum in the
range 5200--6680 \AA with a spectral resolving power of $R$ = 60 000 were
obtained at the 6-m telescope of the Russian Academy of Sciences. Another
optical spectrum in the range 4300--10500 \AA with $R$ = 79 000 was obtained at
the 3.6-m CFHT. Low-resolution spectra in the ranges 0.46--1.4 $\mu$m and
1.4--2.5 $\mu$m with $R \sim$ 800 and $\sim$ 700, respectively, were obtained
at the 3-m Shane telescope of the Lick Observatory. Using a novel kinematical
method based on the non-linear modeling of the neutral hydrogen density profile
in the direction toward the object, we propose a distance of $D = 4.2\pm$0.2
kpc. We also suggest a revised estimate of the star's effective temperature,
T$_{\rm eff} \sim$25 000 K. We resolved the object in both $H$- and $K$-bands.
We conclude that V645 Cyg is a young, massive, main-sequence star, which
recently emerged from its cocoon and has already experienced its protostellar
accretion stage. The presence of accretion is not necessary to account for the
high observed luminosity of (2--6)$\times 10^4$ M$_{\odot}$ yr$^{-1}$. The
receding part of a strong, mostly uniform outflow with a terminal velocity of
$\sim$800 km s$^{-1}$ is only blocked from view far from the star, where
forbidden lines form.
