To provide a storage element device wherein vibration and deflection generated in a storage element module is suppressed to reduce a load applied on fixed parts on its both ends, and to enhance fixing strength, and to lighten it as a result.

Cylindrical battery modules 10 formed by connecting a plurality of unit cells 1 in series are stacked so as to form a plurality of lateral rows and a plurality of steps with equal intervals kept between them. Bus bar plates 70 disposed on both sides of each battery module 10 are made to get engaged with a plus terminal 11 and a minus terminal 12, and the terminals 11, 12 are connected in series by the bus bar 80. The intermediate part of the battery module 10 is rigidly fixed by sandwiching an insulating ring 30 held between the unit cells 1 by the fixed ribs 65 of the fixed plates 60A, 60B disposed in upper and lower parts. A dowel 32 of the insulating ring 30 is fitted in a dowel hole 66 to regulate the rotation of the insulating ring 30.