PURPOSE: To facilitate replacement of each unit by providing positioning projections on the lower part of a recorder that can be bisected, arranging a fitting plate equipped with each unit so as to correspond with the projections, and pressing and stabilizing the recorder by a spring member, etc., on the upper part.

CONSTITUTION: To put together the upper and lower parts 1a and 1b of the picture recorder, the part 1a is pressed down to put a hook 9 over a pin 10 on the lower part 1b. A fixing unit 5 and a transfer belt unit 4 are pressed by a pressure spring 8 and a photosensitive drum 1, respectively, whereby they can operate stably. At the time of maintenance and checking, the hook 9 is removed from the pin 10, and the part 1a is pulled up to pull out a unit fitting plate 6. Then, units 4 and 5 can be simultaneously removed. When the fresh fitting plate 6 equipped with the units 4 and 5 in advance is inserted into positioning projections 7a and 7b, the old one is replaced with the new one, which can be fit in a home position.