PURPOSE: To stabilize the conveyance of sheets by providing a first sheet conveyer means constituted to advance the sheet and follow in the variable conveying direction of the sheet and a second sheet conveyer means for varying the conveying direction widthwise of the sheet.

CONSTITUTION: Sheet holding rollers 30 are rotatably mounted on an arm 31 which in turn is rotably mounted on a shaft 32. Also, since the rollers 30 tend to advance in the direction of exerting the least resistance to a conveyer belt 23 moving before a sheet material is conveyed, the arm 31 carrying the rollers 30 is kept in the direction parallel to the conveyer belt 23. When the sheet material is conveyed between the conveyer belt 23 and rollers 30, the direction of the arm 31 is not varied because of the straight advance of the sheet material for the conveyance thereof. When the sheet material further advances straight and engages with a fixer, however the advancing direction of the sheet material is varied so that the arm 31 is directed parallel to the advancing direction of the sheet material.