To provide a lifting device for a folded double door, capable of preventing a lower door from coming into contact with the end face of a door rack main body in closing the folded double door.

This lifting device is provided with at least one lever having two arms, the longer arm 15 being connected to the lower door 5, and a compression spring element 20, one end of which is rotatably connected to the door rack main body, the other end thereof being rotatably connected to the lever. The lever is guided to displace in the longitudinal direction by a pivot 12, and the shorter arm of the lever is guided in a cam guide 9 fixed to the door rack main body through a slide block or a roller, whereby when the folded double door is closed, the lower door 5 is prevented from coming into contact with the end face of the door rack.