A roller chain with a simple structure is provided, which can mitigate impact load on rollers due to collision with sprockets and can lengthen roller life, as well as minimize interference between the sprockets and inner plates. A roller chain includes rollers that are formed in a cylindrical shape tubularly connected continuously in axial and circumferential directions of the rollers. Each of the rollers is curved such that an inner diameter at both ends thereof differs from that of a middle part, and that their outer diameter at both ends differs from that of the middle part, so that the rollers deform elastically when contacting sprockets S as the rollers are sandwiched between bushings and the sprockets.