PROBLEM TO BE SOLVED: To provide a biological sensor that enables miniaturization while securing authenticity of connection with an electrode of a substrate being inserted and extracted.SOLUTION: A substrate insertion/extraction structure 60 of a biological information acquisition system (biological sensor) includes multiple clip terminals 62 coming in contact with each electrode of a thin substrate 2 for detection while holding the thin substrate 2 for detection, and an enclosure 61 where the multiple clip terminals 62 are fixed at predetermined intervals along the direction being perpendicular to the insertion/extraction direction. The clip terminal 62 is formed by one long metal material being folded back. A first protrusion 62e and a second protrusion 62f protruded toward a portion 62b of the other side are formed in a portion 62a of one side opposed by being folded back. An interval between a tip portion of respective protrusions 62e, 62f of the portion 62a of the one side and the portion 62b of the other side is formed so as to become less than the thickness of the thin substrate 2 for detection while the thin substrate 2 for detection is not inserted.SELECTED DRAWING: Figure 3【課題】挿抜される基板の電極との接続の信頼性を確保しつつ小型化が可能な生体センサを提供する。【解決手段】生体情報取得システム（生体センサ）の基板挿抜構造６０は、検出用薄型基板２を挟持しつつ検出用薄型基板２の各電極に接触する複数のクリップ端子６２と、複数のクリップ端子６２が挿抜方向に直交する方向に沿って所定間隔をあけて固定される筐体６１とを備えている。クリップ端子６２は、一本の長尺状の金属材が折り返されて形成され、当該折り返されることで対向する一方側の部分６２ａに他方側の部分６２ｂに向けて突出する第１凸部６２ｅと第２凸部６２ｆが形成され、検出用薄型基板２が挿入されていない状態で一方側の部分６２ａの各凸部６２ｅ，６２ｆの先端部分と他方側の部分６２ｂとの間隔が検出用薄型基板２の厚み未満となるように形成されている。【選択図】図３
