A pulse wave measuring apparatus includes a pressure sensor having a plurality of sensor elements wider in width than the small sensor element required in conventional tonometry. On the basis of differences .alpha. and .beta. of an AI value based on a pulse wave signal from the sensor element right above an artery and AI values based on pulse wave signals from two sensor elements located at a predetermined distance from the sensor element right above the artery, .alpha..sup.2+.beta..sup.2 is obtained. An AI value correction is calculated using a regression formula with .alpha..sup.2+.beta..sup.2 as a correction parameter representing the distortion degree. Using this correction value, the AI based on a pulse wave signal from the sensor element located right above the artery is corrected.