Disclosed is a cash transaction machine. The cash transaction machine includes a main body including a medium inlet formed on a side of a lower portion thereof and a medium outlet formed on a side of an upper portion thereof, and providing a paper medium fed from the medium inlet to the medium outlet, a transfer module including a driving device mounted on the main body, and a plurality of circulation transfer belts cooperating with the driving device and transferring the paper medium, the plurality of circulation transfer belts being extended to the lower portion of the main body via the medium inlet, and an auxiliary adapter including an adapter box directly or indirectly mounted on the lower portion of the main body, and a belt guidance shaft mounted on the adapter box and positioning an extra part of the circulation transfer belt in the auxiliary adapter.