PROBLEM TO BE SOLVED: To improve detection sensitivity. A pulse wave sensor includes a sensor housing having a first air chamber, an attachment portion having a second air chamber formed by pressing an opening opening on the living body side against a living body surface, and A sensor substrate having a communication hole that connects the first air chamber and the second air chamber, and a cantilever that bends and deforms according to a pressure difference between the pressure inside the first air chamber and the pressure inside the second air chamber, By setting the first air chamber and the second air chamber to have a predetermined volume, the detection of the pressure fluctuation inside the second air chamber based on the bending deformation of the cantilever has a predetermined frequency characteristic, and the pressure fluctuation concerned is detected. And a pulse wave detection unit that detects the pulse wave based on the. [Selection diagram] Fig. 1【課題】検出感度を向上する。【解決手段】脈波センサは、第１空気室を有するセンサ筐体と、生体側に開口された開口部を生体表面に押し当てることで形成される第２空気室を有するアタッチメント部と、第１空気室と第２空気室とを連通する連通孔と、第１空気室の内部の圧力と第２空気室の内部の圧力との圧力差に応じて撓み変形するカンチレバーとを有するセンサ基板と、第１空気室と第２空気室とが所定の容積に設定されることにより、カンチレバーの撓み変形に基づく第２空気室の内部の圧力変動の検出が所定の周波数特性を持ち、当該圧力変動に基づいて脈波を検出する脈波検出部と、からなる。【選択図】図１
