PURPOSE: To smoothly open and close a slide panel by engaging a gear driving roller rotatable in reciprocal directions by a motor with the feed plate part of the side panel.

CONSTITUTION: Running sash rollers 18, 19 are provided on the vertical rail 16 upper end of each slide panel 8, and a rack plate part 23 on the inner side surface of an upper rail 9. A driving roller 37 on the inside of a room is energized toward the panel 8 side and pivotally supported by a case fixed near the door pocket of an upper guide rail 29, and a circular rotating roller 47 is provided on the outside of the room. The panel 8 is disposed between both the rollers 37, 47 in such a manner that the roller 37 is engaged with the plate part 23 of the panel 8. Further, a motor is driven to rotate the roller 37 in reciprocal directions, whereby the panel 8 is opened and closed.