PURPOSE: To allow a sliding door type automatic door to be automatically opened or manually opened so as to be able to secure a delivery goods insert opening of required minimum size at the lower corner on the door closing side at the time of switching to a shop closing mode in a sliding door type automatic door device with the sliding door type automatic door automatically opened/closed in a shop opening mode.

CONSTITUTION: When a shop closing mode is selected, a sliding door type automatic door D is connected to an intrusion preventing fence 9 through a door-fence connecting device 8. At the time of desiring to insert delivery goods inside the automatic door D, a door opening signal is inputted from a shop closing time door opening/closing signal input device 10. The sliding door type automatic door D is thereby opened automatically into a specified position or opened into the specified position by manual door opening operation. As the sliding door type automatic door D is opened, the intrusion preventing fence 9 is pulled out from a door frame so as to close the opening equivalent to the opened part of the sliding door type automatic door D and to secure a delivery goods insert opening P of required size on the lower side. The delivery goods Q can be thereby inserted from this opening P.