To provide a paper sheet reversing mechanism for reversing a carried paper sheet without generating time loss nor requiring complicated control and capable of reducing a space for reversing the paper sheet, and to provide an image forming device using the same.

This paper sheet reversing mechanism 10 for reversing and delivering a paper sheet, which is carried from outside has a feeding means 13 for carrying the carried paper sheet from a carry-in opening 11 to a carry-out opening 12. A carrying surface of a carrying passage (c) for the paper sheet P to be carried by the feeding means 13 is twisted at 180° around an axis in the carrying direction.