A platen plate for supporting an ejection object for liquid droplets ejected from each nozzle on the bottom surface of a liquid ejection head can secure the flatness of the ejection object so as to appropriately eject ink as well as can prevent the contamination of the bottom surface of the ejection object. The platen plate is provided with a plurality of ribs raised from its bottom surface so as to extend in a conveying direction of a recording sheet and arranged at predetermined intervals in a width wise direction of the recording sheet, and out of a region where ink droplets ejected from the each nozzle are landed, the bottom surface of the recording sheet is supported with top faces of the ribs so as to define a distance between the recording sheet and the ink ejection surface, and within the region where ink droplets ejected from the each nozzle are landed, the rib top faces are formed to have a height, or the ribs themselves do not exist, so that the rib top faces are not brought into contact with the bottom surface of the recording sheet.