An electric storage device includes an electric storage device body impregnated with an electrolyte solution, a sheath for hermetically sealing the electric storage device body, and a pressure regulator provided at the sheath. The pressure regulator includes a plurality of gas release mechanism portions. Further, the pressure regulator allows release of gases from an inside space of the sheath in which the electric storage device body exists to an outside space by causing the gases from the inside space to pass through the gas release mechanism portions in succession, and blocks entry of gases from the outside space to the inside space by the respective gas release mechanism portions. A buffer space is formed between the gas release mechanism portions by being partitioned by the gas release mechanism portions.