To prevent the cracking and improve the durability by constituting a bumper body from a hard rubber, and constituting at least outer surface part of a dust cover from a material resistant to ozone deterioration.

A bumper 1 is formed of a bumper body 7 and a dust cover 6. The body 7 has a thick bellows form having a through-hole 8 for pressing a piston rod 3 in the center part, and it is formed of a hard rubber excellent in durability to compression such as a synthetic material of natural rubber with butadiene rubber, natural rubber or the like. The cover 6 has a cylindrical form continued to the outer edge of the bottom part 9 of the body 7 and concentric to the through-hole 8, and it is formed of a material hardly cracked by ozone deterioration such as ethylene propylene rubber, nitrile rubber and the like. It is further formed into a thin bellows having a contact thickness. The body 7 and the cover 6 are integrally molded by injection molding. Thus, the surface of the cover 6 can be prevented from being cracked by ozone deterioration. Further only the outer surface part of the cover 6 may be formed of a material resistant to ozone deterioration.