PURPOSE: To easily replace a head cartridge to prevent the movement of the fxing position of the head cartridge when the head cartridge is mounted on a head carriage.

CONSTITUTION: A head cartridge K1 constituted of a case-shape head support member 61 and the ink jet recording head fixed within the head support member 61 has a member 62b to be prevented from slip-out and a head carriage has cartridge placing parts 22b, 22c formed to the side surface of the cartridge mounting hole 22 having an almost rectangular cross section permitting the insertion of the lower end part of the head cartridge from above. When the head cartridge K1 placed on the cartridge placing parts 22b, 22c is pushed rearwardly by a press member 51, the member 62 to be prevented from slip-out is engaged with a slip-out preventing hole 22d.