A metal bellows for an accumulator into which a hydraulic fluid or a pressure gas is drawn in, the metal bellows being a cylindrical member having a bellows-shape in which ridge fold portions on its radially outer side and valley fold portions on its radially inner side are formed and in which the ridge fold portions and the valley fold portions are repeatedly formed with slope portions in between, wherein when the metal bellows is in a free length state, two of the slope portions that are adjacent to each other via a common ridge fold portion have: first slope portions (110c1) each of which extends from the common ridge fold portion toward adjacent valley fold portions; and second slope portions (110c2) each of which extends from each of the first slope portions (110c1) extending from the common ridge fold portion toward the adjacent valley fold portions such that a distance therebetween becomes greater than a distance between the adjacent first slope portions (110c1) as the second slope portions (110c2) extend toward the adjacent valley fold portions, wherein a width of the ridge fold portion becomes narrower toward its crest, and a distance between the adjacent ridge fold portions becomes greater toward the radially outer side, a width of the valley fold portion becomes narrower toward its crest, and a distance between the adjacent valley fold portions becomes greater toward the radially inner side, and when the metal bellows is in a maximal compression state, the adjacent ridge fold portions come into contact with each other, characterized by the first slope portions (110c1) each of which extends parallelly from the common ridge fold portion toward the adjacent valley fold portions such that the distance therebetween remains constant, the second slope portions (110c2) each of which extends straight from each of the first slope portions (110c1) extending from the common ridge fold portion toward the adjacent valley fold portions with gradients that are greater than gradients of the adjacent first slope portions (110c1), and when the metal bellows is in a maximal compression state, the adjacent valley fold portions do not come into contact with each other, and the adjacent slope portions do not come into contact with each other. first slope portions (110c1) each of which extends from the common ridge fold portion toward adjacent valley fold portions; and second slope portions (110c2) each of which extends from each of the first slope portions (110c1) extending from the common ridge fold portion toward the adjacent valley fold portions such that a distance therebetween becomes greater than a distance between the adjacent first slope portions (110c1) as the second slope portions (110c2) extend toward the adjacent valley fold portions, wherein a width of the ridge fold portion becomes narrower toward its crest, and a distance between the adjacent ridge fold portions becomes greater toward the radially outer side, a width of the valley fold portion becomes narrower toward its crest, and a distance between the adjacent valley fold portions becomes greater toward the radially inner side, and when the metal bellows is in a maximal compression state, the adjacent ridge fold portions come into contact with each other, characterized by the first slope portions (110c1) each of which extends parallelly from the common ridge fold portion toward the adjacent valley fold portions such that the distance therebetween remains constant, the second slope portions (110c2) each of which extends straight from each of the first slope portions (110c1) extending from the common ridge fold portion toward the adjacent valley fold portions with gradients that are greater than gradients of the adjacent first slope portions (110c1), and when the metal bellows is in a maximal compression state, the adjacent valley fold portions do not come into contact with each other, and the adjacent slope portions do not come into contact with each other.