To provide a roller conveyer that not only facilitates mounting work of a driving part but also allows safe work without requiring concerning of an obstacle under a frame during work around the driving roller conveyer.

A driving body DP having a built-in small motor M is stored and mounted together with a specific cross member 10, so that the mounting work of the driving part DP is facilitated, and safe work is allowed without requiring concerning of the obstacle under frames 2a and 2b also during the work around the driving roller conveyer.