Provided is a congestive heart failure therapy device that applies positive pressure within an optimal range depending on the condition of the congestive heart failure (CHF) patient. Provided is a positive pressure therapy device for congestive heart failure patients, comprising: a pressure raising part for raising the pressure of air, or a mixed gas of air and another gas, to a positive pressure； an introducing part for introducing the air or the mixed gas that has been brought to a positive pressure into the airways of the patient； and a blood oxygen level measurement part for measuring the blood oxygen level of the patient, a blood flow measurement part for measuring the blood flow of the patient, or a cardiac output measuring part for measuring the cardiac output of the patient. A control part monitors the blood oxygen levels, the blood flow or the cardiac output and, if the value is less than or equal to a fixed value, it is determined that the positive pressure being applied is not suitable and the control part controls the pressure raising part so as to change a positive pressure value. By controlling the pressure raising part while monitoring the blood oxygen levels, the blood flow or the cardiac output, positive pressure can be applied within the optimal range in accordance with the preload state of the congestive heart failure patient.
