PURPOSE: To provide a stacking device which is so good at controllability that even long-size sheets can be stacked without being dropped or folded.

CONSTITUTION: A stacking device 27 is provided with a separating member 30 for dividing a stacking surface 27a into two of upper and lower stages and a folding guide 31 is provided at that portion of the printer main body 10 of the stacking device 27 which is opposite to a sheet outlet 26. When long-size sheets S are used, the sheets S to be discharged from the sheet outlet 26 are folded at the folding guide 31 and are stacked on the stacking surface 27a and the separating member 30.