PURPOSE: To prevent the damage of a picture image face by separating a preceding sheet by stopping the driving of a transfer means when the preceding sheet of the sheet group superposed by sliding its tip part is separated from the transfer means, in the sheet transfer device of a copying machine, etc.

CONSTITUTION: The sheet group Sn superposed by sliding in order the tip part in the transfer direction is fed to a feeding means 31 by being interposed by a transfer means 29. When a preceding sheet S1 reaches the feeding means 31 and further is passed through the transfer means 29, the passing of the preceding sheet S1 is detected by a detection means 74, the transfer operation of the transfer means 29 is stopped, the transfer operation of the feeding means 31 is started and the preceding sheet S1 is transferred by separating from the other sheet. The sheet group Sn is fed to the transfer means 31 in order from the preceding sheet S1 and whenever the sheet is passed through the transfer means 29 the transfer operation of the transfer means 29 is stopped, yet the transfer operation of the feeding means 31 is started and it is separated and transferred one by one.