of the single piece positioning member 101 a referential code 101 e denotes the surface by which the single piece positioning member is attached to the cover 19 or 20 of the cartridge 15 the lip portions of the walls of the receptacle portion 101 a which surrounds the gap 101 g into which the main portion 102 a of the fastening member 102 is inserted are chamfered to make easier the insertion of the main portion 102 a a referential code f 1 denotes the distance between the end surfaces 101 h of the walls surrounding the gap 101 g and the hole 101 d fig1 is a perspective view of a fastening member 102 as seen from the direction corresponding to the direction from which the single piece positioning member 101 is seen in fig9 fig1 is a perspective view of the fastening member 102 as seen from the direction corresponding to the direction from which the single piece positioning member 101 is seen in fig1 the main portion 102 a of the fastening member 102 is provided with a pair of recesses 102 b which perfectly correspond to the position of the single piece positioning member 101 and a pair of claw portions 102 c which latch into the corresponding holes 101 d of the single piece positioning member 101 the pair of arm portions 102 d of the fastening member 102 are the portions that elastically deform to allow the pair of claw portions 102 c to fit into the holes 101 d they can be elastically deformed by grasping the fastening member by the handle portions 102 e in a manner.