To provide a surface and back surface turn-over device capable of surely turning over a surface and a back surface of paper sheets.

In this surface and back surface turn-over device, a carrying belt 17 is stretched in a curved surface obliquely along the longitudinal direction of a turn-over member 16, and paper sheets are carried, while being wound around the curved surface, and turned over, while rotating. Furthermore, in the case wherein the paper sheets comprise a lot of moisture under high-temperature and high-humidity environment or in the case wherein the paper sheets 4 has a lot of crinkles, when the paper sheet 14 is moved, while being brought in contact with the guide surface, a load is generated when turning over, and jam and bias feeding of the paper sheets 14 are easy to be generated. Guide surfaces 33a and 33b are provided with gas injection holes 40 and 41 to float the paper sheets 14 from the guide surfaces 33a and 33b, and as a result, friction resistance of the paper sheets 14 in relation to the guide surfaces 33a and 33b is reduced to prevent the generation of jam and bias feeding of the paper sheets 14.