  In order to study the possible superconductivity at the polar surfaces of
1111-type iron-based superconductors, which is doped with a large amount of
holes in spite of the electron doping in bulk materials, we have performed
angle-resolved photoemission spectroscopy (ARPES) studies on superconducting
PrFeAsO$_{1-y}$~crystals. We have indeed observed the opening of a
superconducting gap on surface-derived hole pockets as well as on a
bulk-derived hole pocket. The superconducting gap is found to open on the
surface-derived hole pockets below the bulk $T_c$, which suggests that the
surface superconductivity is possibly induced by proximity effect from the
bulk. We have also observed the opening of a large pseudogap on the
surface-derived hole pockets, which is similar to the pseudogap in 122-type
bulk superconductors doped with a smaller amount of holes. This suggests that
the opening of a large pseudogap is a characteristic property of hole-doped
iron-based superconductors.
