A blood pressure measurement apparatus includes a measuring device that includes a plurality of pressure sensors and is for measuring blood pressure information for each heartbeat in a measurement target, and an arrangement state inferring unit for extracting a feature quantity from an output waveform of each of the pressure sensors for each heartbeat, and inferring an arrangement state of the measuring means relative to an artery that is the measurement target based on a distribution profile of values of the feature quantity for the plurality of pressure sensors. The apparatus also includes a reliability calculating unit for calculating a reliability of the blood pressure information measured by the measuring means, based on the inferred arrangement state.
