Welded bellows are manufactured by stamping sheets of metal into diaphragms and welding the inside and outside edges of them. Welded bellows are remarkable in that any metal can be manufactured into bellows if it can be welded. An especially remarkable feature is that the number of convolutions is theoretically unlimited. The bellows are manufactured to have excellent elasticity and bendability, while retaining high hermeticity in a manufacturing process that requires outstanding technology. Welded bellows are attracting attention as a high-performance part which supports the semiconductor, liquid crystal, nuclear power, medical device and other high-tech industries.