[Object] 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. [Solution] A dialysate extraction apparatus includes a dialysate extraction device 9 that has an introduction port 9a and a discharge port 9b which are connected to a flow route of a liquid and can circulate the liquid and that has a collection port 9c which can collect the circulated liquid； a cap 10 that is attachable to and detachable from the collection port 9c of the dialysate extraction device 9 and can open and close the collection port 9c； a sealing device 11 that is attached to the cap 10 and seals the collection port 9c in a state where the cap 10 is attached to the collection port 9c of the dialysate extraction device 9； and a heating device 12 that can heat the sealing device 11 of the cap 10.
