An ink-jet printing machine has: a transfer belt that transfers a printing sheet; a sheet feeding unit that feeds the printing sheet; an ink-jet head that performs ink ejection on the printing sheet; a SS roller that presses a central region of the printing sheet between the sheet feeding unit and the ink-jet head; a printing sheet sensor that detects the deformation of the printing sheet; and a guide roller that presses the printing sheet. The rate of a distance A between the SS roller and the printing sheet sensor to a distance B between the upper surface of a transfer belt and the lower end of the printing sheet sensor is approximately equal to the rate of a distance A′ between the guide roller and the ink-jet head to a distance B′ between the upper surface of the transfer belt and the lower end of the ink-jet head.