A spitting device for an inkjet head includes an array type inkjet head on which nozzle units are formed, and a platen which is disposed opposite to the nozzle units of the inkjet head. The platen includes ink outlets and printing medium guide ribs formed thereon, and supports a back surface of a printing medium. The platen includes a first platen unit and a second platen unit which is movably connected to the first platen unit and on which second printing medium guide ribs are formed. The spitting device can prevent the printing medium guide ribs from being contaminated by ink ejected from the nozzle units and allows the printing medium to be more stably fed during high-speed printing.