PROBLEM TO BE SOLVED: To provide an electrocardiographic waveform measuring apparatus which is not likely to be influenced by electrostatic noise due to a seat body covering material which covers a sensor electrode when the sensor electrode is disposed on a seat body material in an exposed state.SOLUTION: An electrocardiographic waveform measuring apparatus 1 has a sensor electrode 2 disposed on a seat interior side, which is the rear surface of a user contact surface 100h of a separate seat body covering material 101 covering a seat body material 102. The sensor electrode 2 comprises: a first sensor electrode 2X having a first electrode surface 2Xa which is installed on the seat body material 102 and is exposed to the seat body covering material 101 side and a second sensor electrode 2Y having a second electrode surface 2Ya which is installed on the seat body covering material 101 and slidably comes into contact with the first electrode surface 2Xa.COPYRIGHT: (C)2015,JPO&INPIT【課題】 シート本体材上にセンサ電極を露出して配置されるにあたって、これを覆うシート本体被覆材による静電気ノイズの影響を受け難いようにした心電波形計測装置を提供する。【解決手段】 心電波形計測装置1は、シート本体材102を覆う別体のシート本体被覆材101のユーザー接触面100hの裏側となるシート内部側にセンサ電極2が設けられるとともに、センサ電極2は、シート本体材102に取り付けられてシート本体被覆材101側に露出する第一電極表面2Xaを有する第一センサ電極2Xと、シート本体被覆材101に取り付けられて第一電極表面2Xaに対し摺動可能に接触する第二電極表面2Yaを有する第二センサ電極2Yと、からなる。【選択図】図3