An endoscope reprocessor includes: a liquid supply nozzle including a lifting conduit configured to feed a liquid in a direction against gravity and a turndown conduit； a liquid ejection port； a treatment tank configured to receive the liquid ejected from the liquid ejection port, the treatment tank allowing an endoscope to be placed inside； a liquid sampling port provided in a connection portion； and a relief cap including a cover configured to cover the liquid sampling port, a fitting portion configured to make the cover be detachably attachable to the connection portion, and an opening/closing portion configured to, if an inner pressure of the liquid supply nozzle exceeds a predetermined value, eject the liquid in a direction with gravity.
