A battery pack, comprising: a module stack body having a plurality of stacked battery modules; a first end plate provided on one end of the module stack body; a second end plate provided on the other end of the module stack body; a first connecting member extending in the stacking direction of the plurality of battery modules to hold the plurality of stacked battery modules; a second connecting member disposed in the same surface of the first connecting member and extending in the stacked direction of the plurality of battery modules to hold the plurality of the stacked battery modules; a first reinforcing member that is fixed to the first connecting member at a first fixed point and fixed to the second connecting member at a second fixed point; a second reinforcing member that is fixed to the first connecting member at a third fixed point and fixed to the second connecting member at a fourth fixed point, a first fixing bolt for fastening the first end plate and the first connecting member; a second fixing bolt for fastening the first end plate and the second connecting member; a third fixing bolt for fastening the second end plate and the first connecting member; and a fourth fixing bolt for fastening the second end plate and the second connecting member, wherein: - each of the axial directions of the first to fourth fixing bolts extends in a direction perpendicular to a side surface, - the orientation (Va) of a component along the stacking direction of the battery modules of a vector directing from the first fixed point toward the second fixed point and the orientation (Vb) of a component along the stacking direction of the battery modules of a vector directing from the third fixed point toward the fourth fixed point are opposite to each other, and - the first fixed point and the third fixed point are the same point or the second fixed point and the fourth fixed point are the same point. a module stack body having a plurality of stacked battery modules; a first end plate provided on one end of the module stack body; a second end plate provided on the other end of the module stack body; a first connecting member extending in the stacking direction of the plurality of battery modules to hold the plurality of stacked battery modules; a second connecting member disposed in the same surface of the first connecting member and extending in the stacked direction of the plurality of battery modules to hold the plurality of the stacked battery modules; a first reinforcing member that is fixed to the first connecting member at a first fixed point and fixed to the second connecting member at a second fixed point; a second reinforcing member that is fixed to the first connecting member at a third fixed point and fixed to the second connecting member at a fourth fixed point, a first fixing bolt for fastening the first end plate and the first connecting member; a second fixing bolt for fastening the first end plate and the second connecting member; a third fixing bolt for fastening the second end plate and the first connecting member; and a fourth fixing bolt for fastening the second end plate and the second connecting member, wherein: - each of the axial directions of the first to fourth fixing bolts extends in a direction perpendicular to a side surface, - the orientation (Va) of a component along the stacking direction of the battery modules of a vector directing from the first fixed point toward the second fixed point and the orientation (Vb) of a component along the stacking direction of the battery modules of a vector directing from the third fixed point toward the fourth fixed point are opposite to each other, and - the first fixed point and the third fixed point are the same point or the second fixed point and the fourth fixed point are the same point. - each of the axial directions of the first to fourth fixing bolts extends in a direction perpendicular to a side surface, - the orientation (Va) of a component along the stacking direction of the battery modules of a vector directing from the first fixed point toward the second fixed point and the orientation (Vb) of a component along the stacking direction of the battery modules of a vector directing from the third fixed point toward the fourth fixed point are opposite to each other, and - the first fixed point and the third fixed point are the same point or the second fixed point and the fourth fixed point are the same point.