A secondary battery cell includes: a case in which an electrode assembly is accommodated; a cap plate assembly coupled to at least one side of the case; and a venting unit including a base coupled to one surface of the case and a notch portion formed on the base, and the notch portion includes: a first notch portion extending in a first direction; a second notch portion extending in a second direction intersecting the first direction; and a third notch portion extending in a third direction, parallel to a longitudinal direction of the base from both ends of the first notch portion and the second notch portion.