To provide an imaging apparatus in which troubles caused by paper powder generated upon breakage of a recording medium, e.g. a roll sheet, can be prevented and the recording medium is attracted sufficiently to a platen.

A receiving groove 62 is defined by a pair of side walls 64, 64 and a bottom wall 66. The pair of side walls 64, 64 are formed integrally with a platen 16 and the bottom wall 66 is formed separately from the pair of side walls 64, 64. The up/down moving shaft 69 of a solenoid 68 is secured to the bottom face of the bottom wall 66. When the solenoid 68 is turned on, the up/down moving shaft 69 descends to separate the bottom wall 66 from the pair of side walls 64, 64 thus forming a gap (opening) between them. When the solenoid 68 is turned off, the up/down moving shaft 69 ascends to bring the bottom wall 66 into tight contact with the pair of side walls 64, 64 thus forming no gap between them.