The purpose of the invention is to provide a biological information acquiring device that has low power consumption and can acquire an accurate pulse waveform even when there is body movement. A biological information acquiring device comprises one or a plurality of multi-axis pressure sensors to detect the pressure in two or more axial directions that intersect at a prescribed angle, and a computing device to compute the output of the multi-axis pressure sensors. The multi-axis pressure sensor comprises a signal detecting means for detecting a signal for each axial pressure component of the pulse wave of the subject being measured. The computing device comprises a pulse waveform synthesizing means for synthesizing a pulse waveform from the signals for the axial pressure components detected by the multi-axis pressure sensor.