A seat slide device includes a handle rotatably supported in holding holes provided respectively at a pair of upper rails to rotate a radial projection portion for releasing a lock mechanism, and a bearing member having an outer edge portion disposed between the upper rail and the radial projection portion formed at the handle, a holding portion disposed between the upper rail and the outer periphery of the handle, and a cushioning portion allowing the handle to move in an axial direction. The bearing member is disposed to fit into the holding hole for supporting the handle.