A hemodialysis apparatus 1 is provided with a dialysate filter, and an inspection passage for discharging a fluid from one of a space on the inflow side or a space on the discharge side, opening means 42 for opening the other space to the air, pressure detecting means for detecting pressure fluctuation in the one space, and judgment means 54 for determining acceptability of the dialysate filter on the basis of the pressure fluctuation are provided. The control means discharges the dialysate from the one space through the inspection passage by a dialysate pump 52 and also opens the other space to the air by the opening means 42, and when the pressure of the one space is reduced to a first negative pressure, the pressure is reduced to a second negative pressure by draining means. The judgment means determines that the dialysate filter is non-defective if the pressure detecting means does not detect the pressure fluctuation from the second negative pressure and determines that the filter is defective if it detects the pressure fluctuation. Leak check of the dialysate filter can be conducted rapidly and accurately.
