To provide a sealed battery with a safety mechanism in which no leakage of an electrolyte solution is caused by a shock of falling or the like.

In the sealed battery provided with a safety mechanism in which a valve is crushed to discharge the gas inside the battery out of the battery, when a battery inner pressure rises, the valve is arranged on a sealing port plate for sealing an outer can bottom or an opening of the outer can, and the thickness of the valve is thinner than the thickness of the outer can bottom or the sealing port plate and moreover the valve has a crushing groove to open the valve, and a chamfering part of which the corners are chamfered are formed on at least part of a battery outside face of the body in an interface between the valve and the can bottom of the outer can where the valve is arranged or the body of the sealing port plate.