  P-wave pentaquarks with strangeness +1, I=0 and J^P=1/2^+ are studied in the
non-relativistic quark model with instanton induced interaction (III). We
present their mass splittings and orbital-spin-isospin-color structures. It is
found that decompositions of the wave functions are sensitive to III, while the
mass splittings are insensitive. The decay of the lowest energy pentaquark,
\Theta^+, is found to be suppressed when the contribution of III is increased.
Its wave function is dominated by Jaffe-Wilczek-type configuration at large
III.
