To provide a sliding door device without needing execution of a guide rail, reinforced substrate material or the like on an opening part side and mountable even in an opening part or the like without the guide rail.

The device is improvement of a sliding door device moving a door body in parallel in a face in the horizontal direction for an opposite face member. A guide means 3 is provided in one of the door body 1 and the opposite face member 2, and a sliding means 4 for being guided by the guide means is provided on the other of the door body 1 and opposite face member 2. A double sliding door device is made by making the opposite face member 2a second door body, and the single sliding or sliding door device is made by making the opposite face member 2 a fixed face member.