To provide a stacker capable of surely stacking and accommodating even a single sheet of weak stiffness.

This stacker is provided with a loading space 20 vertically movably mounted on a device frame 10 and loading and accommodating the fed single sheet, a pressing plate 30 vertically movably mounted on the device frame 10 for intermittently pressing down the uppermost sheet of the single sheet loaded on the loading space, and an actuator 40 for vertically moving the pressing plate.