A battery block includes assembled batteries that are arranged in parallel to each other, and the plurality of assembled batteries are each formed of a plurality of batteries as a unit. Each of the batteries has a positive-electrode terminal and a negative-electrode terminal on one end portion of the battery. The assembled battery includes: the plurality of batteries which are arranged in a row with one end portions of the batteries directed in the same direction; an insulation holder which is arranged on one end portion side of the batteries and holds the batteries; and a positive-electrode bus bar and a negative-electrode bus bar arranged on one end portions of the batteries. The positive-electrode bus bar and the negative-electrode bus bar are respectively held by holding portions which are formed on the insulation holder along a row direction and in parallel to each other.