is possible to aim at miniaturizing the apparatus as a whole and at lowering the cost thereof and further to eliminate noise caused by a ventilating fan referring to fig2 which is a sectional view illustrating an essential part of an electrophotographic printing apparatus incorporating a facsimile device in a second embodiment of the present invention a cassette 43 in which printing sheets 42 are stored and stacked is loaded in the bottom part of a vertically long housing 41 the printing sheets 42 are led out leftward from the cassette 43 by a frictional force of a paper feed roller 44 which is located in front of the cassette 43 when the feed roller 44 is rotated by a predetermined angle further a guide part 48 is laid along the inner wall of the housing 41 so that the printing sheet 42 led out from the cassette 43 is conveyed along this guide part 48 a developing unit 45 is located in the bottom part of the housing 41 and a photosensitive medium drum 46 is located above the developing unit 45 an image transfer unit 47 lined with an ozone adsorbing material is provided on one side of the photosensitive medium drum 46 further on other side.