The present invention is a blood processing apparatus having a heat exchanger having a first space and a second space, wherein a first fluid flows in the first space, and a second fluid flows in the second space. A capacitor element having a membrane through which fluid flows and the heat exchanger has a membrane separating the first space from the second space, the membrane having two capacitor plates located on opposite sides of the membrane； And a blood processing apparatus in which monitoring means configured to detect electrical characteristics of the capacitor is connected to the capacitor for the purpose of detecting leakage from the first space to the second space. . [Selection] Figure 2本発明は、第１の空間と第２の空間とを有する熱交換器を有する血液処理装置であって、前記第１の空間に第１の流体が流れ、前記第２の空間に第２の流体が流れ、前記熱交換器が、前記第１の空間を前記第２の空間から分離する膜を有し、該膜が、該膜の両側に位置する２つのコンデンサプレートを有するコンデンサの要素を形成し、前記コンデンサに、前記第１の空間から前記第２の空間への漏れを検出する目的で前記コンデンサの電気的特性を検出するように構成されたモニタリング手段が接続された血液処理装置に関する。【選択図】図２
