  To explore the electronic structure of the first aromatic superconductor,
potassium-doped solid picene which has been recently discovered by Mitsuhashi
et al with the transition temperatures $T_c=7 - 20$ K, we have obtained a
first-principles electronic structure of solid picene as a first step toward
the elucidation of the mechanism of the superconductivity. The undoped crystal
is found to have four conduction bands, which are characterized in terms of the
maximally localized Wannier orbitals. We have revealed how the band structure
reflects the stacked arrangement of molecular orbitals for both undoped and
doped (K$_3$picene) cases, where the bands are not rigid. The Fermi surface for
K$_3$picene is a curious composite of a warped two-dimensional surface and a
three-dimensional one.
