  We present the results of mid-infrared N-band spectroscopy of the Herbig
Ae/Be system MWC1080 using the Cooled Mid-Infrared Camera and Spectrometer
(COMICS) on board the 8m Subaru Telescope. The MWC1080 has a geometry such that
the diffuse nebulous structures surround the central Herbig B0 type star. We
focus on the properties of polycyclic aromatic hydrocarbons (PAHs) and PAH-like
species, which are thought to be the carriers of the unidentified infrared
(UIR) bands in such environments. A series of UIR bands at 8.6, 11.0, 11.2, and
12.7um is detected throughout the system and we find a clear increase in the
UIR 11.0um/11.2um ratio in the vicinity of the central star. Since the UIR
11.0um feature is attributed to a solo-CH out-of-plane wagging mode of cationic
PAHs while the UIR 11.2um feature to a solo-CH out-of-plane bending mode of
neutral PAHs, the large 11.0um/11.2um ratio directly indicates a promotion of
the ionization of PAHs near the central star.
