It is intended to provide a method whereby the peritoneal function of a dialysis patient can be tested by a relatively easy procedure and yet a high accuracy can be achieved compared with the existing methods, and an apparatus for the peritoneal function test by using the same. Standards of four kinetic parameters ( CCr, Kt/V, MTACu, and MTACc) available in a definite dialysis guideline are computed in accordance with the relational expression (formula (7)). The curve showing the relation between MTACu/c thus obtained 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.
