The monastery library and treasury are located above the [[narthex]] of the katholikon. The library contains 409 manuscript codices, of which 20 are written on parchment, and some 4,000 printed books. Xeropotamou holds a number of pieces of the True Cross, including the largest piece. This piece, which contains one of the holes left by the nails that fastened Christ to the Cross, is set in a wooden crucifix. Additionally there are many [[
relic]] s of [[saint]]s, episcopal staffs, vestments and [[liturgical objects]] in the monastery treasury.