A measuring apparatus comprising: a blood pressure calculator which is configured to measure first and second blood pressure values of a subject; and a blood pressure estimating section which is configured to estimate a third blood pressure value based on a ratio relating the first, second, and third blood pressure values; a pulse wave measuring section which is configured to measure a pulse wave of the subject; and a pressure controller which is configured to pressurize a predetermined portion of the subject during measurement of the pulse wave, wherein the blood pressure estimating section is configured to calculate the ratio based on a shape of the pulse wave which is measured by the pulse wave measuring section, wherein the ratio is between a difference between a mean arterial blood pressure and a diastolic blood pressure, and a difference between a systolic blood pressure and the mean arterial blood pressure; and the pressure controller is configured to pressurize the predetermined portion of the subject by a pressure which is equal to or higher than a predetermined pressure that is equal to or higher than a venous pressure, wherein further the first blood pressure value is a diastolic blood pressure; and the second blood pressure value is a mean blood pressure, and the third blood pressure value is a systolic blood pressure, or the second blood pressure value is a systolic blood pressure, and the third blood pressure value is a mean blood pressure; characterized in that the measuring apparatus further comprises: a MAP calculator which is configured to calculate a change of a %MAP, Percentage of Mean Artery Pressure, from a pressurizing force of the pressure controller, and a waveform of the pulse wave, to calculate an estimated value of the %MAP in a case where the pressurization by the pressure controller is cancelled, based on the change of the %MAP and to set the estimated value of the %MAP as the ratio. a blood pressure calculator which is configured to measure first and second blood pressure values of a subject; and a blood pressure estimating section which is configured to estimate a third blood pressure value based on a ratio relating the first, second, and third blood pressure values; a pulse wave measuring section which is configured to measure a pulse wave of the subject; and a pressure controller which is configured to pressurize a predetermined portion of the subject during measurement of the pulse wave, wherein the blood pressure estimating section is configured to calculate the ratio based on a shape of the pulse wave which is measured by the pulse wave measuring section, wherein the ratio is between a difference between a mean arterial blood pressure and a diastolic blood pressure, and a difference between a systolic blood pressure and the mean arterial blood pressure; and the pressure controller is configured to pressurize the predetermined portion of the subject by a pressure which is equal to or higher than a predetermined pressure that is equal to or higher than a venous pressure, wherein further the first blood pressure value is a diastolic blood pressure; and the second blood pressure value is a mean blood pressure, and the third blood pressure value is a systolic blood pressure, or the second blood pressure value is a systolic blood pressure, and the third blood pressure value is a mean blood pressure; characterized in that the measuring apparatus further comprises: a MAP calculator which is configured to calculate a change of a %MAP, Percentage of Mean Artery Pressure, from a pressurizing force of the pressure controller, and a waveform of the pulse wave, to calculate an estimated value of the %MAP in a case where the pressurization by the pressure controller is cancelled, based on the change of the %MAP and to set the estimated value of the %MAP as the ratio.