PROBLEM TO BE SOLVED: To provide a pulse wave sensor having improved measurement accuracy. SOLUTION: The attachment portion 13 has a first sensor chamber 11 and a second sensor chamber 12 in which the internal pressure changes in response to the pulsation of the living body S, and is pressed against the living body surface S1, and the internal pressure change in the first sensor chamber. A first pulse wave detection unit having a first pressure sensor 20 that is displaced according to the internal pressure and outputting a first pulse wave signal corresponding to the internal pressure change, and a second pulse wave detection unit that is displaced according to the internal pressure change of the second sensor chamber. A second pulse wave detection unit that has a pressure sensor 30 and outputs a second pulse wave signal according to the change in internal pressure, detects a pulse wave based on the first pulse wave signal, and is based on the second pulse wave signal. The present invention provides a pulse wave sensor 4 including a processing unit for detecting a pressing state of the attachment unit against the surface of a living body. [Selection diagram] Fig. 3【課題】測定精度が向上した脈波センサを提供すること。【解決手段】生体Ｓの脈動に対応して内圧が変化する第１センサ室１１及び第２センサ室１２を有し、生体表面Ｓ１に押し当てられるアタッチメント部１３と、第１センサ室の内圧変化に応じて変位する第１圧力センサ２０を有し、該内圧変化に応じた第１脈波信号を出力する第１脈波検出部と、第２センサ室の内圧変化に応じて変位する第２圧力センサ３０を有し、該内圧変化に応じた第２脈波信号を出力する第２脈波検出部と、第１脈波信号に基づいて脈波を検出すると共に第２脈波信号に基づいて生体表面に対するアタッチメント部の押し当て状態を検出する処理部とを備えている脈波センサ４を提供する。【選択図】図３
