A metal bellows (110) for an accumulator (100) into which a hydraulic fluid is drawn in, has a bellows-shape in which ridge fold portions (110a) and valley fold portions (110b) are formed repeatedly with slope portions (110c) in between, wherein two of the slope portions (110c) that are adjacent to each other via a common ridge fold portion (110a) have: first slope portions (110c1) which extend from the common ridge fold portion (110a) and second slope portions (110c2) each of which extends from each of the first slope portions (110c1) such that a distance therebetween becomes much greater than the first slope portions (110c1) as the second slope portions (110c2) extend toward the adjacent valley fold portions (110b), wherein the first slope portion (110c1) and the second slope portion (110c2) are connected at an inflection point (P).