the under surface of the main flat portion 228 etc can be effectively prevented in addition should such dew formation occur in the main flat portions 208 and 228 etc the dews are not likely to adhere to the paper 242 because the paper 242 passing between the lower guide plate 204 and the upper guide plate 206 advances through the paper moving passage defined by the upper edges of the rising pieces 238 and the lower edges of the hanging pieces 240 and makes contact only with very limited areas of the upper edges of the rising pieces 238 and the lower edges of the hanging pieces 240 consequently no deterioration due to the adhesion of dews occurs in the paper 242 itself or the toner image formed on it nor is there paper jamming as a result of the smooth movement of the paper 242 being hampered by the dew formation in more detail when relatively large dew drops form on the upper side of the main flat portion 208 of the lower guide plate 204 or the side surfaces of the rising pieces 238 these dew drops are not likely to adhere to the paper 242 but when relatively large dew drops form on the underside of the main flat portion 228 of the upper guide plate 206 or on the side surfaces of the hanging pieces 240 these dew drops are likely to.