A peritoneal function testing apparatus tests the peritoneal function of a dialysis patient easily and with high accuracy. Standards of four kinetic parameters (CCr, Kt/V, MTACu, and MTACc) available in a definite dialysis guideline are computed in accordance with a relational expression, and a curve showing the relation between MTACu/c and the drained fluid volume is indicated in a graph together with the PET data of the patient which has been prepared separately. Thus, the peritoneal function can be evaluated based on the relative position of the patients data and the curve showing the standard values in the graph.
