To provide a highly reliable power storage device which improves vibration resistance, impact resistance, water resistance, and heat radiation.

A power storage device 100 includes: power storage cells 10, each of which has an outer covering body 12 where a positive electrode, a negative electrode, an electrolytic solution are housed; a housing 20 where the power storage cells 10 are housed; and a resin body 30 filling the housing 20 and fixing the power storage cells 10. The interior of the housing is divided into an outer covering body housing region 21 and a terminal housing region 22. Further, the multiple power storage cells are connected and heat sinks are provided between the power storage cells.