A belt is disposed in a main body and moves circularly to transport a recording medium placed thereon. A cleaning roller contacts an outer surface of the belt for removing extraneous matter deposited on the outer surface of the belt. A pair of backup rollers is disposed in opposition to the cleaning roller with the belt interposed between the backup rollers and the cleaning roller. The pair of backup rollers contacting the belt at first and second positions and the cleaning roller contacting the belt at a third position where the third position is interposed between the first and second positions. A holder rotatably holds the pair of backup rollers. Rotational axes of the backup rollers are kept parallel to each other. An urging unit urges the backup rollers toward the cleaning roller. A driving unit is supported on the main body and moves the holder to change a distance between the pair of backup rollers and the cleaning roller.