An apparatus and method for projecting a spatial image is disclosed. In one embodiment, the apparatus includes i) a monitor, which outputs the spatial image, ii) an image direction control unit, which controls the direction of the spatial image outputted from the monitor and controls a viewing angle, and iii) a half-mirror, which transflects the spatial image whose direction is adjusted by the image direction control unit. At least one embodiment of the present invention modifies the conventional barrier technology, which has been used to control 3D images or viewing angles, to enhance a sense of realism by adjusting the direction of light emitted from a display device.