PROBLEM TO BE SOLVED: To provide an electrode bonding structure and a biosensor in which disconnection of wiring is suppressed. A biological sensor 100 is composed of a pressure-sensitive adhesive layer 110 having a sticking surface to be attached to a subject and a conductive polymer having elasticity, and is exposed from the sticking surface of the pressure-sensitive adhesive layer. The maximum diameter of the steel ball, which is provided so as to overlap the opposite surface of the pressure-sensitive adhesive layer to which the electrode 140 is attached and is stopped by the ball rolling method of J.Dow ball tack, is 0.4 mm or more and 4 mm or less. Includes a base material layer 120, a substrate 133 provided on the base material layer, a wiring 131 provided on the substrate and connected to the electrode, and a joint portion 145 for joining the electrode and the wiring. .. [Selection diagram] Fig. 1【課題】配線の断線を抑制した電極接合構造及び生体センサを提供する。【解決手段】生体センサ１００は、被検体に貼り付けられる貼付面を有する感圧接着層１１０と、伸縮性を有する導電性高分子で構成され、前記感圧接着層の前記貼付面から表出する電極１４０と、前記感圧接着層の貼付面の反対面に重ねて設けられ、J.Dowボールタックの球転法で停止する鋼球の最大直径が０．４ｍｍ以上４ｍｍ以下のタック性を有する基材層１２０と、前記基材層上に設けられる基板１３３と、前記基板に設けられ、前記電極に接続される配線１３１と、前記電極と前記配線とを接合する接合部１４５とを含む。【選択図】図１
