A display apparatus comprising: a camera comprising an image sensor for sensing an image passed through a lens, the camera being mounted to be movable up/down on a top of the display apparatus, and to be moved up and ejected outward from the display apparatus when it is in use; an image processor configured to process an image signal corresponding to an image taken by the camera; a display configured to display an image based on the processed image signal; a detector configured to detect movement of the camera; a user input interface; a power supply configured to supply power to elements of the display apparatus; and characterised by a controller configured to: control the power supply to turn on the display of the display apparatus, while the display of the display apparatus is powered off, in response to the user input interface receiving a user's input or in response to the detector detecting that the camera moves from the interior of a housing of the display apparatus to project from a surface of the display apparatus; identify, based on the detector detecting that the camera moves to the interior of the housing of the display apparatus while the display of the display apparatus is powered on, whether the display of the display apparatus was turned on in response to the projection of the camera or in response to the user's input; control the power supply to turn off the display of the display apparatus based on identifying that the display of the display apparatus was turned on in response to the projection of the camera; and control the display to display, based on identifying that the display of the display apparatus was turned on in response to the user's input, a screen displayed on the display before the camera moves to project from the surface of the display apparatus after the display of the display apparatus was turned on in response to the user's input. a camera comprising an image sensor for sensing an image passed through a lens, the camera being mounted to be movable up/down on a top of the display apparatus, and to be moved up and ejected outward from the display apparatus when it is in use; an image processor configured to process an image signal corresponding to an image taken by the camera; a display configured to display an image based on the processed image signal; a detector configured to detect movement of the camera; a user input interface; a power supply configured to supply power to elements of the display apparatus; and characterised by a controller configured to: control the power supply to turn on the display of the display apparatus, while the display of the display apparatus is powered off, in response to the user input interface receiving a user's input or in response to the detector detecting that the camera moves from the interior of a housing of the display apparatus to project from a surface of the display apparatus; identify, based on the detector detecting that the camera moves to the interior of the housing of the display apparatus while the display of the display apparatus is powered on, whether the display of the display apparatus was turned on in response to the projection of the camera or in response to the user's input; control the power supply to turn off the display of the display apparatus based on identifying that the display of the display apparatus was turned on in response to the projection of the camera; and control the display to display, based on identifying that the display of the display apparatus was turned on in response to the user's input, a screen displayed on the display before the camera moves to project from the surface of the display apparatus after the display of the display apparatus was turned on in response to the user's input. control the power supply to turn on the display of the display apparatus, while the display of the display apparatus is powered off, in response to the user input interface receiving a user's input or in response to the detector detecting that the camera moves from the interior of a housing of the display apparatus to project from a surface of the display apparatus; identify, based on the detector detecting that the camera moves to the interior of the housing of the display apparatus while the display of the display apparatus is powered on, whether the display of the display apparatus was turned on in response to the projection of the camera or in response to the user's input; control the power supply to turn off the display of the display apparatus based on identifying that the display of the display apparatus was turned on in response to the projection of the camera; and control the display to display, based on identifying that the display of the display apparatus was turned on in response to the user's input, a screen displayed on the display before the camera moves to project from the surface of the display apparatus after the display of the display apparatus was turned on in response to the user's input.