A post-processing device comprising: an evacuation drum that is rotatably supported by a main shaft and rotates in a first direction to wind a sheet-shaped body around a peripheral surface thereof; a first branching guide that has a substantially triangle shape of which base faces the drum, and is rotatably supported at a position more on outside than the base in a radial direction of the evacuation drum by a shaft parallel to the main shaft, in which an apex of the first branching guide on an upstream side in a winding direction of the evacuation drum and an apex of the first branching guide on a downstream side in the winding direction of the evacuation drum can be in contact with and separated from the peripheral surface of the evacuation drum by rotation of the first branching guide, the first branching guide forming a gap from the evacuation drum through which the sheet-shaped body can pass when the apexes (63b, 63c) are separated from the peripheral surface of the evacuation drum; a first driving unit adapted such that it rotationally moves the first branching guide and rotates the evacuation drum; and characterized in that the post-processing device further comprises a control unit adapted such that, in response to an instruction to reverse the sheet-shaped body, the control unit controls the first driving unit such that: the gap is formed between the first branching guide and the evacuation drum; the evacuation drum rotates in the winding direction; the sheet-shaped body passes through the gap and is wound around the evacuation drum; the apex of the first branching guide on the downstream side in the winding direction is in contact with the peripheral surface of the evacuation drum; the evacuation drum rotates in a counter-winding direction; the sheet-shaped body is separated from the evacuation drum; and the sheet-shaped body is ejected with a face, which is opposite to a top face upon winding, directed upward, along a side other than the base face of the first branching guide, and wherein, in response to an instruction of ejection without reversing the sheet-shaped body, the control unit controls the first driving unit such that: the evacuation drum rotates in the winding direction; the apex of the first branching guide on the upstream side in the winding direction is in contact with the peripheral surface of the evacuation drum; the sheet-shaped body is separated from the evacuation drum; and the sheet-shaped body is ejected along another side other than the base face of the first branching guide, with a face, which is the top face upon winding, directed upward. the gap is formed between the first branching guide and the evacuation drum; the evacuation drum rotates in the winding direction; the sheet-shaped body passes through the gap and is wound around the evacuation drum; the apex of the first branching guide on the downstream side in the winding direction is in contact with the peripheral surface of the evacuation drum; the evacuation drum rotates in a counter-winding direction; the sheet-shaped body is separated from the evacuation drum; and the sheet-shaped body is ejected with a face, which is opposite to a top face upon winding, directed upward, along a side other than the base face of the first branching guide, and wherein, in response to an instruction of ejection without reversing the sheet-shaped body, the control unit controls the first driving unit such that: the evacuation drum rotates in the winding direction; the apex of the first branching guide on the upstream side in the winding direction is in contact with the peripheral surface of the evacuation drum; the sheet-shaped body is separated from the evacuation drum; and the sheet-shaped body is ejected along another side other than the base face of the first branching guide, with a face, which is the top face upon winding, directed upward. the evacuation drum rotates in the winding direction; the apex of the first branching guide on the upstream side in the winding direction is in contact with the peripheral surface of the evacuation drum; the sheet-shaped body is separated from the evacuation drum; and the sheet-shaped body is ejected along another side other than the base face of the first branching guide, with a face, which is the top face upon winding, directed upward.