A electricity storage module is provided with a stack formed by stacking a plurality of electricity storage elements having positive and negative lead terminals that protrude outward from end portions thereof and insulating holder members made of an insulating material for holding the electricity storage elements. A connecting portion formed by connecting different polarized lead terminals of adjacent electric cells is disposed in a position shifted from other connecting portions than that connecting portion as seen from the stacking direction of the stack, and the insulating holder members are provided with windows that correspond to the connecting portions.