A liquid ejection apparatus, comprising: a liquid-ejection head having a plurality of ejection openings and configured to eject liquid through the ejection openings to record an image on a recording medium; a sealing mechanism (40 (41,42,43),8a) configured to selectively establish (i) a sealed state in which an ejection space in which the ejection openings are open is sealed from an outside and (ii) an unsealed state in which the ejection space is not sealed from the outside; a humid-air supply mechanism configured to supply a humid air into the ejection space; and a controller configured to control the sealing mechanism, the humid-air supply mechanism, and the liquid-ejection head, wherein, the controller is configured to control, during the sealed state of the ejection space established by the sealing mechanism, the humid-air supply mechanism to supply the humid air into the ejection space wherein a humidity in the ejection space becomes higher than a predetermined appropriate value and one of a density and a viscosity of the liquid to be ejected from the ejection openings becomes less than a predetermined value, wherein the controller is configured to control the liquid-ejection head such that at least a preset amount of liquid is preliminarily ejected through the ejection openings as a preliminary ejection in the sealed state prior to the ejection of the liquid onto the recording medium for recording the image on the recording medium, and wherein the controller is configured to set the preset amount such that the larger a difference between (i) a first humidity in the ejection space when one of the density and the viscosity of the liquid in the ejection openings becomes the predetermined value and (ii) a second humidity that is a humidity in the ejection space when the humid air has been supplied and that becomes higher than the first humidity, the larger the preset amount becomes. a liquid-ejection head having a plurality of ejection openings and configured to eject liquid through the ejection openings to record an image on a recording medium; a sealing mechanism (40 (41,42,43),8a) configured to selectively establish (i) a sealed state in which an ejection space in which the ejection openings are open is sealed from an outside and (ii) an unsealed state in which the ejection space is not sealed from the outside; a humid-air supply mechanism configured to supply a humid air into the ejection space; and a controller configured to control the sealing mechanism, the humid-air supply mechanism, and the liquid-ejection head, wherein, the controller is configured to control, during the sealed state of the ejection space established by the sealing mechanism, the humid-air supply mechanism to supply the humid air into the ejection space wherein a humidity in the ejection space becomes higher than a predetermined appropriate value and one of a density and a viscosity of the liquid to be ejected from the ejection openings becomes less than a predetermined value, wherein the controller is configured to control the liquid-ejection head such that at least a preset amount of liquid is preliminarily ejected through the ejection openings as a preliminary ejection in the sealed state prior to the ejection of the liquid onto the recording medium for recording the image on the recording medium, and wherein the controller is configured to set the preset amount such that the larger a difference between (i) a first humidity in the ejection space when one of the density and the viscosity of the liquid in the ejection openings becomes the predetermined value and (ii) a second humidity that is a humidity in the ejection space when the humid air has been supplied and that becomes higher than the first humidity, the larger the preset amount becomes.