An electrochemical element in which a safety mechanism can be normally operated even when an accident happens. The electrochemical element comprises an exhaust valve which is operated, when the internal pressure in a case (4) reaches a predetermined value, so as to discharge the generated gas in the case to the outside; and a holed plate (2) which has hole parts (5a, 5b) and is installed between an electrode group (3) and the exhaust valve. The area of the holed plate (2) excluding the hole parts (5a, 5b) is 20 to 50% of the area of the case opening. The holed plate (2) has a function for electrically insulating the electrode group (3) from a sealing plate (1).