A processing apparatus comprising: a processing unit is configured to perform a predetermined process on a medium (P); a placement unit on which the medium (P) can be placed in a first posture in which a surface of the medium (P) is placed along a placement surface of the placement unit ; a medium feeding unit configured to feed the medium (P) from the placement unit toward the processing unit ; and a feed unit that is detachably disposed on the placement unit , wherein the feed unit is configured to cause the medium (P) to be placed in a second posture which is different from the first posture in which, of four sides of the medium (P), an end side on a downstream side in a transport direction is brought into contact with a placement surface of the feed unit and the medium (P) is inclined; characterised in that the medium feeding unit has a first gear on a shaft of a feed roller which is one constituent member, and the feed unit has a second gear , wherein the first gear and the second gear intermesh with each other with the feed unit disposed on the placement unit , the feed unit further includes a roller configured to feed the medium (P) toward the medium feeding unit , and the roller is configured to rotate, with power from the medium feeding unit transmitted thereto via the first gear and the second gear ; wherein the medium (P) having the first posture can be fed out by the medium feeding unit in a state in which a surface of the medium (P) is placed along the placement surface of the placement unit , configured such that, when the medium (P) having the second posture moves to a position of the roller and passes through the position of the roller , with the end side of the medium (P) on the downstream side sliding on the placement surface of the feed unit , the posture of the surface of the medium (P) changes along the placement surface of the feed unit , and the medium is fed to the medium feeding unit by the roller . a processing unit is configured to perform a predetermined process on a medium (P); a placement unit on which the medium (P) can be placed in a first posture in which a surface of the medium (P) is placed along a placement surface of the placement unit ; a medium feeding unit configured to feed the medium (P) from the placement unit toward the processing unit ; and a feed unit that is detachably disposed on the placement unit , wherein the feed unit is configured to cause the medium (P) to be placed in a second posture which is different from the first posture in which, of four sides of the medium (P), an end side on a downstream side in a transport direction is brought into contact with a placement surface of the feed unit and the medium (P) is inclined; characterised in that the medium feeding unit has a first gear on a shaft of a feed roller which is one constituent member, and the feed unit has a second gear , wherein the first gear and the second gear intermesh with each other with the feed unit disposed on the placement unit , the feed unit further includes a roller configured to feed the medium (P) toward the medium feeding unit , and the roller is configured to rotate, with power from the medium feeding unit transmitted thereto via the first gear and the second gear ; wherein the medium (P) having the first posture can be fed out by the medium feeding unit in a state in which a surface of the medium (P) is placed along the placement surface of the placement unit , configured such that, when the medium (P) having the second posture moves to a position of the roller and passes through the position of the roller , with the end side of the medium (P) on the downstream side sliding on the placement surface of the feed unit , the posture of the surface of the medium (P) changes along the placement surface of the feed unit , and the medium is fed to the medium feeding unit by the roller . <EOS>