  We have experimentally revealed the band structure and the surface Brillouin
zone of insulating picene single crystals (SCs), the mother organic system for
a recently discovered aromatic superconductor, with ultraviolet photoelectron
spectroscopy (UPS) and low-energy electron diffraction with laser for
photoconduction. A hole effective mass of 2.24 m_0 and the hole mobility mu_h
>= 9.0 cm^2/Vs (298 K) were deduced in Gamma-Y direction. We have further shown
that some picene SCs did not show charging during UPS even without the laser,
which indicates that pristine UPS works for high-quality organic SCs.
