A movement-guiding device that includes a moving rail having a rolling element rolling surface; a first block that engages with the rolling element rolling surface of the moving rail via a plurality of rolling elements; a fixed rail including a rolling element rolling surface; a second block that engages with the rolling element rolling surface of the fixed rail via a plurality of rolling elements; and a joint member. The joint member is formed in a plank shape and connects the moving rail and the fixed rail by having the first block mounted on one surface and having the second block mounted on the other surface. The joint member is formed having a height difference.