An inkjet printing apparatus comprising: a stacking unit configured to stack printing medium substantially horizontally; a print head having an ejection opening surface located vertically above the stacking unit, on which a plurality of ejection openings for ejecting ink are provided, the print head being configured to perform printing by ejecting ink to a print medium fed from the stacking unit; a platen configured to support the back side of a print medium in a position facing the ejection opening surface of the print head; a discharging unit located vertically above the print head, on which a print medium subjected to printing by the print head is discharged; and a conveying unit (7,7a,7b) configured to convey a print medium subjected to printing by the print head vertically upwards toward the discharging unit, wherein the ejection opening surface faces the platen in a case where the inkjet printing apparatus is in a printing state and faces vertically downward in a case where the inkjet printing apparatus is in a maintenance state; and the platen supports the back side of a print medium at an angle from 30° to 60° with respect to a horizontal direction; characterized in that the stacking unit includes a first stacking unit configured to stack first printing medium and a second stacking unit located vertically below the first stacking unit and configured to stack second printing medium that are larger in size than the first printing medium, the ejection opening surface is located in a position included in an area vertically above an area occupied by the second stacking unit and not included in an area vertically above an area occupied by the first stacking unit in a case where the inkjet printing apparatus is in the printing state, a case where the inkjet printing apparatus is in a standby state, and a case where the inkjet printing apparatus is in the maintenance state, wherein the standby state is a state in which the ejection opening surface faces vertically downward and is capped with a cap unit. a stacking unit configured to stack printing medium substantially horizontally; a print head having an ejection opening surface located vertically above the stacking unit, on which a plurality of ejection openings for ejecting ink are provided, the print head being configured to perform printing by ejecting ink to a print medium fed from the stacking unit; a platen configured to support the back side of a print medium in a position facing the ejection opening surface of the print head; a discharging unit located vertically above the print head, on which a print medium subjected to printing by the print head is discharged; and a conveying unit (7,7a,7b) configured to convey a print medium subjected to printing by the print head vertically upwards toward the discharging unit, wherein the ejection opening surface faces the platen in a case where the inkjet printing apparatus is in a printing state and faces vertically downward in a case where the inkjet printing apparatus is in a maintenance state; and the platen supports the back side of a print medium at an angle from 30° to 60° with respect to a horizontal direction; characterized in that the stacking unit includes a first stacking unit configured to stack first printing medium and a second stacking unit located vertically below the first stacking unit and configured to stack second printing medium that are larger in size than the first printing medium, the ejection opening surface is located in a position included in an area vertically above an area occupied by the second stacking unit and not included in an area vertically above an area occupied by the first stacking unit in a case where the inkjet printing apparatus is in the printing state, a case where the inkjet printing apparatus is in a standby state, and a case where the inkjet printing apparatus is in the maintenance state, wherein the standby state is a state in which the ejection opening surface faces vertically downward and is capped with a cap unit.