PROBLEM TO BE SOLVED: To provide an automatic blood pressure measuring apparatus capable of obtaining a correct measurement value of a diastolic blood pressure.SOLUTION: An automatic blood pressure measuring apparatus subtracts a systolic phase time phase wave PVRsys from a cuff volume pulse wave PVR obtained in a section where a pressing pressure is lower than a systolic phase end-diastolic pressure, thereby extracts a diastolic phase composite wave PVRdia included in the cuff volume pulse wave PVR. Because a diastolic blood pressure value of living body can be calculated on the basis of amplitudes of the diastolic phase composite wave PVRdia which is not affected by the systolic phase time phase wave PVRsys included in the cuff volume pulse wave PVR, the automatic blood pressure measuring apparatus can obtain a highly accurate measurement value of the diastolic blood pressure.
