Abstract: An electrical storage device includes a plurality of power-generating elements, a case, and a valve. The power-generating elements perform charge and discharge and are connected electrically in series. A plurality of housing sections each accommodate one of the plurality of power-generating elements and are disposed along a predetermined direction. A communication path switches from a closed state to an opened state depending on the internal pressure of the housing section. When the communication path is in the opened state, gas can be moved between two of the housing sections adjacent to each other in the predetermined direction. The valve is provided for a particular housing section and releases gas produced within the case to the outside of the case. The empty space other than the power-generating element is present in each of the housing sections, and the empty space in the particular housing section is the largest.