A dialysate-extracting apparatus in which a collecting port can be disinfected with no disinfecting work to be performed by a worker. A dialysate-extracting apparatus includes a dialysate-extracting device having an introduction port and a discharge port each of which is connected to the flow route for liquid and allows the liquid to flow therethrough, and a collecting port from which the liquid flowing in the flow route is collectable; and an opening-and-closing device that is movable between a closing position where the opening-and-closing device covers the collecting port of the dialysate-extracting device and an opening position where the opening-and-closing device 6 opens the collecting port. The dialysate-extracting apparatus further includes an ultraviolet-applying device attached to the opening-and-closing device and that is capable of applying ultraviolet rays to the collecting port when the opening-and-closing device is at the closing position.