A liquid ejection apparatus comprising: a liquid ejection head having ejection openings for ejecting liquid; a capping mechanism which causes an ejection space opposing the ejection openings to take either one of a sealed state in which the ejection space is separated from an external space and a non-sealed state in which the ejection space is connected to the external space, the capping mechanism including an annular component which surrounds the ejection space in the sealed state and an opposing member which opposes the ejection openings with the ejection space interposed therebetween; the annular component comprises an elastic member including a base portion connected to a fixing component by a connecting portion; a mechanism for supplying humidified air, adapted to generate humidified air and including a supply opening through which the humidified air is supplied into the ejection space separated from the external space by the capping mechanism and a discharging opening through which air is discharged from the ejection space; and a control unit adapted to control the capping mechanism so that the ejection space takes either one of the sealed state and the non-sealed state and controls the mechanism for supplying humidified air so that the humidified air is supplied to the ejection space in the sealed state through the supply opening and the humidified air is discharged through the discharging opening, the supply opening and the discharging opening are positioned to form a humidifying passage in one direction such that the humidified air having flown along an inner circumferential surface of a first region of the annular component passes through a gap between the ejection openings and the opposing member and flows along an inner circumferential surface of a second region of the annular component, which opposes the first region, the liquid ejection apparatus being characterized by a first guide which constitutes the supply opening which is open toward the inner circumferential surface of the first region so that the humidified air is supplied toward the inner circumferential surface of the first region; and a second guide which constitutes the discharging opening which is open toward the inner circumferential surface of the second region so that air around the inner circumferential surface of the second region is discharged, wherein at the end portions of the first and second guide in a subscanning direction, the inner circumferential surface of the connection portion (41 d) contacts the corner portions of the first and second guide. a liquid ejection head having ejection openings for ejecting liquid; a capping mechanism which causes an ejection space opposing the ejection openings to take either one of a sealed state in which the ejection space is separated from an external space and a non-sealed state in which the ejection space is connected to the external space, the capping mechanism including an annular component which surrounds the ejection space in the sealed state and an opposing member which opposes the ejection openings with the ejection space interposed therebetween; the annular component comprises an elastic member including a base portion connected to a fixing component by a connecting portion; a mechanism for supplying humidified air, adapted to generate humidified air and including a supply opening through which the humidified air is supplied into the ejection space separated from the external space by the capping mechanism and a discharging opening through which air is discharged from the ejection space; and a control unit adapted to control the capping mechanism so that the ejection space takes either one of the sealed state and the non-sealed state and controls the mechanism for supplying humidified air so that the humidified air is supplied to the ejection space in the sealed state through the supply opening and the humidified air is discharged through the discharging opening, the supply opening and the discharging opening are positioned to form a humidifying passage in one direction such that the humidified air having flown along an inner circumferential surface of a first region of the annular component passes through a gap between the ejection openings and the opposing member and flows along an inner circumferential surface of a second region of the annular component, which opposes the first region, the liquid ejection apparatus being characterized by a first guide which constitutes the supply opening which is open toward the inner circumferential surface of the first region so that the humidified air is supplied toward the inner circumferential surface of the first region; and a second guide which constitutes the discharging opening which is open toward the inner circumferential surface of the second region so that air around the inner circumferential surface of the second region is discharged, wherein at the end portions of the first and second guide in a subscanning direction, the inner circumferential surface of the connection portion (41 d) contacts the corner portions of the first and second guide.