To provide a dialysate extraction apparatus which can automate disinfecting work for a collection port or a sealing device of an opening/closing device and can reliably and easily clean the collection port or the sealing device of the opening/closing device. A dialysate extraction apparatus includes a dialysate extraction device that has an introduction port and a discharge port which are connected to a flow route of a liquid and can circulate the liquid and that has a collection port which can collect the circulated liquid； a cap that is attachable to and detachable from the collection port of the dialysate extraction device and can open and close the collection port； a sealing device that is attached to the cap and seals the collection port in a state where the cap is attached to the collection port of the dialysate extraction device； and a heating device that can heat the sealing device of the cap.
