  We present our spectroscopic observations of V455 Andromedae during the 2007
superoutburst. Our observations cover this superoutburst from around the
optical peak of the outburst to the post-superoutburst stage. During the early
superhump phase, the emission lines of Balmer series, He I, He II, Bowen blend,
and C IV / N IV blend were detected. He II 4686 line exhibited a double-peaked
emission profile, where Balmer emission lines were single-peaked, which is
unexpected from its high inclination. In the ordinary superhump phase, Balmer
series transitioned to double-peaked emission profiles, and high-ionization
lines were significantly weakened. These transitions of the line profiles
should be related to the structural transformation of the accretion disk, as
expected between the early and ordinary superhump transition in the
thermal-tidal instability model. The Doppler map of H$\alpha$ during the early
superhump phase exhibits a compact blob centered at the primary white dwarf. In
analogy to SW Sex-type cataclysmic variables, this feature could emerge from
the disk wind and/or the mass accretion column onto the magnetized white dwarf.
The Doppler map of He II 4686 \AA~ is dominated by the ring-like structure and
imposed two flaring regions with the velocity of $\sim$300 km/s, which is too
slow for a Keplerian accretion disk. The phase of the flaring regions was
coincident with the inner spiral arm structure identified during the early
superhump phase. Our disk wind model with the enhanced emission from the inner
arm structure successfully reproduced the observed properties of He II 4686
\AA. Therefore, V455 And is the first case in dwarf nova outbursts that the
presence of the disk wind is inferred from an optical spectrum.
