To provide a sea chest which can effectively eliminate bubbles mixed in the sea chest together with sea water, and to prevent an adverse effect on the navigation performance of a ship.

In the sea chest 1 comprising a sea water inlet 4 provided on the ship to take in sea water outboard the ship to feed the sea water inboard the ship and a sea water outlet 5 for discharging the sea water taken in from the sea water inlet 4 outboard the ship, a regulating means 8 for regulating the sea water flow from the sea water inlet 4 to the sea water outlet 5 is provided between the sea water inlet 4 and the sea water outlet 5, and the flow of sea water flowing into the sea water outlet 5 forms a downstream by the regulating means 8.