A paper storage apparatus for stacking and storing paper in sequence comprising a first discharge roller 21 for discharging paper (check S1) in a specified discharge direction; a paper storage pocket (check storage pocket 12) for stacking the paper at a position offset from the specified direction in which the check S1 is transported by the first discharge roller 21, a movable first guide member (paper guide 60) having a first position disposed at an inclined angle relative to the direction the check S1 is discharged by the first discharge roller 21, for guiding the check S1 into the storage pocket 12, and a second position displaced from the first position for applying pressure upon the check(s)in the check storage pocket 12 and a movable second guide member (paper shift lever) 40 positioned between the first discharge roller 21 and first guide member (paper guide 60) which pivots from a first position in response to the leading edge of the paper to allow the paper to advance into a second position for urging the trailing edge of the paper toward the movable second guide member.