To provide a dust boot provided with a bellows which is hard to cause barrel-bent when it expands and contracts.

In the dust boot 7 which covers the peripheries of a rod part 2 and a cylinder part 3 of a damper device to prevent the entering of dust, the pitch P between bellows of the bellows part is kept constant, the height (D-d) of the crest is changed in sequence in multiple stages, the thickness is formed in sequence in multiple stages, and the spring constant of the bellows is formed sequentially in multiple stages so that the bellows can be folded in order, and thus to eliminate the barrel-bent of the bellows. The dust boot provided with such a bellows can be simply manufactured by blowing, namely by spraying compressed air into a bag-like raw material obtained by melting elastic thermoplastic resin to expand the raw material like a balloon, and the dust boot is suited to mass production.