SLIDING DOOR DEVICE

PROBLEM TO BE SOLVED: To provide a sliding door device allowing no clearance under a sliding door, with adequate durability and easy maintenance.SOLUTION: A sliding door device 1 is configured to run a door roller RL2 equipped in a sliding door 11 along a horizontal traveling rail SR equipped in a doorway opening TB. The doorway opening is equipped with a driving rail KR along the opening/closing direction of the sliding door with a slope to the traveling rail. The sliding door is equipped with a driving device KS including a driving roller RL1 that can roll on the surface of the driving rail and a compression coil spring 26 that exerts a force on the driving roller in the direction vertical to the traveling rail so as to press the roller toward the surface of the driving rail. Since the driving roller is pressed in a direction not perpendicular to the surface of the driving rail, a driving force is given to the sliding door in the closing direction, allowing the sliding door to close automatically.