PURPOSE: To permit easy manufacture by pressing a guide plate for a transfer inlet by means of springs to side plates of a dielectric belt cassette so that the specified space between the surface of the dielectric belt and an auxiliary guide plate for transfer is maintained.

CONSTITUTION: The space between the auxiliary guide plate 15 for transfer and the dielectric belt 5 is assured by contact between the side plates 1, 2 and the plate 15. The plate 15 is used to guide recording paper 23 fed by rollers 22, 21 in succession to the guide plate 19 for transfer to the belt 5 and to bring the same into contact with the belt. Said plate is so installed to the side plates on the paper feed side in a way as to be turned clockwise around a fulcrum shaft 24 by means of the pressing springs 25. The top end of said plate is pressed to the bottom ends 17, 18 of the plates 1, 2 and is thereby positioned. The space between the dielectric belt and the auxiliary guide plate for transfer is thus kept uniformly within a specification and the manufacture is made easy.