Electrodes (A, B) are provided in at least one of plate-like members corresponding to an inner side direction of supply path from an opening of supply path. Electrode (C) of a biological sample is provided in the inner side direction from electrodes (A, B) Reagent part is provided so as to cover electrodes (A, B) and electrode (C). Inflow restricting hole of a sample liquid is provided in at least one of plate-like members corresponding to the portions on both sides of supply path closer to the opening side than the electrode.