To prevent breakage by abnormal deformation when seal function of a seal section becomes ineffective to cause pressurized liquid remaining in the liquid chamber to be lost, a metallic bellows-type accumulator having a metal bellows, a bellows cap, an outer gas chamber and an inner liquid chamber, in a shell is structured to have a bellows constructed such that, when pressure in the liquid chamber (12) is further reduced after the bellows cap (31) is brought into contact with an oil port (4), surface contact sections (35) are formed on the metal bellows (3) and a curvature radius of U-shaped sections (3A) of crest portions (32) at the outer diameter side is reduced, and a curvature radius of U-shaped sections (3A) of root portions (33) at the inner diameter side is enlarged.