PROBLEM TO BE SOLVED: To provide an electroconductive polymer fiber that has excellent conductivity, excellent strength in dry state and wet state, and excellent flexibility, and a bioelectrode comprising the same.SOLUTION: An electroconductive polymer fiber 40 is obtained by impregnating a base material fiber 41 with an electric conductor 42 comprising an electroconductive polymer and/or attaching the electric conductor 42 to the base material fiber 41, in which between the plurality of base material fibers, the electric conductor is disposed in close contact with the base material fibers.SELECTED DRAWING: Figure 6【課題】導電性、乾燥状態及び湿潤状態における強度、並びに柔軟性に優れた導電性高分子繊維と、それを備えた生体電極を提供する。【解決手段】基材繊維41に、導電性高分子を含む導電体42が含浸及び/又は付着されてなる導電性高分子繊維40であって、複数の前記基材繊維の間に、前記導電体が前記基材繊維に密着して配されていることを特徴とする導電性高分子繊維40。【選択図】図6