Temperature of the intake air required is configured to be disposed between the breathing circuit connected to the ventilator or anesthetic circuit is connected to the anesthesia apparatus and the patients respiratory system, patients under artificial respiration or anesthesia and wet heat exchanger to maintain the humidity includes a heat storage unit and a moist heat recycled materials are added to the heat storage unit. Density of heat storage section, the number of cells in the heat storage section, and at least one of the added amount of heat and humidity recycled materials heat storage section inside, the ventilator side or the anesthesia machine from the patient side along the flow direction of the breath of heat storage section inside you have decreases towards.患者の呼吸器系と麻酔器に接続された麻酔回路または人工呼吸器に接続された呼吸回路との間に配されるよう構成された、麻酔下または人工呼吸下の患者に必要な吸気の温度及び湿度を維持するための湿熱交換器は、蓄熱部と、蓄熱部に添加された湿熱再生材料とを含む。蓄熱部の密度、蓄熱部のセル数、及び蓄熱部内部の湿熱再生材料の添加量のうちの少なくとも一つが、蓄熱部内部の呼気の流向に沿って患者側から麻酔器または人工呼吸器側に向かって減少している。
