Air purifier

An air purifier comprising:

• a main body having an inlet;
• and
• a discharge device mounted on the main body and configured to receive air introduced into the main body through the inlet and discharge the air from the air purifier,
• wherein the discharge device includes:
• a discharge opening located at an upper side of the discharge device;
• a first case fixed to the main body and having a first discharge portion including a first plurality of discharge holes, wherein each discharge hole of the first plurality of discharge holes has a size smaller than a size of the discharge opening;
• a second case disposed to cover the first case, and having a second discharge portion disposed to be opposite to the first discharge portion to cover the first discharge portion and including a second plurality of discharge holes, wherein each discharge hole of the second plurality of discharge holes has a size smaller than the size of the discharge opening;
• and
• an opening and closing member including a portion having a size and shape corresponding to the discharge opening, and configured to move out of the discharge opening and into the discharge opening in a vertical direction to open and close the discharge opening,
• wherein the second case is moveable with respect to the first case in a vertical direction so that the second discharge portion to enabled to uncover a portion of the first discharge portion,
• wherein at least the first discharge portion and the second discharge portion has an air discharging area that increases as the second case moves in a direction away from the first case, and decreases as the second case moves in a direction toward the first case.