In a method for forming product stacks of folded or unfolded product blanks made of paper or chemical pulp, product blanks are supplied consecutively to a stacking surface and placed in an upright position. A separating element is inserted between two consecutive product blanks as the product blanks are moved against a channel wall of a discharge channel for temporary support of a rear side of the product blanks, to thereby form a first product stack with a predetermined number of product blanks between the separating element and the channel wall. The channel wall is opened to thereby allow the first product stack to be transferred to the discharge channel, and a sliding element is inserted between the product stack and a subsequent second product stack, as the first product stack is moved to the discharge channel.

A paper sheet insertion apparatus (for example, depositing and dispensing unit 20) includes: an imaging unit (for example, camera 60) configured to take an image of a side edge portion, on a placement member 23a side, of paper sheets placed in a placement unit 22, or a side edge portion, on a side opposite to the placement member 23a side, of the paper sheets placed in the placement unit 22, to obtain image data; and a control unit (for example, depositing and dispensing unit control unit 72) configured to determine, based on the image data obtained by the imaging unit, whether or not a plurality of the paper sheets placed in the placement unit are bundled by a bundling member.

A paper sheet handling apparatus includes a movable unit that changes a size of a taking-out space by moving in a direction of approaching a paper sheet discharged to the taking-out space and a direction of retreating the paper sheet, in which the movable unit includes a movable unit main body and a pressing unit movable to a storage position where the pressing unit is moved along the movable unit main body and a pressing position where the pressing unit presses the paper sheet.