Provided are a liquid tank capable of reducing an influence of disturbance on measurement results and measuring accurate volume, and a fuel cell using the same. One face of a liquid container section is structured by a detector in which a first board to a fourth board each configured of a printed board are stacked in order. A pair of detection electrodes 12A and 12B are provided on a front face of the first board, and this pair of detection electrodes 12A and 12B are allowed to contact directly or indirectly to a liquid fuel inside the liquid container section to detect a stray capacitance. A back face side of the first board is disposed with the second board having a shielding electrode 22. Even when a hand or the like is brought close to the detector, the detection electrodes 12A and 12B are prevented from sensing the stray capacitance generated as a result.