The present invention relates to a mobile device-attachable/detachable cosmetic case comprising: a cosmetic case having a first and a second palette coupled to each other in a tiltable and swivelable manner, the first and the second palette each having a reception portion for selectively receiving a tray for receiving the cosmetic or a mirror in an attachable/detachable manner; and a cradle which supports the cosmetic case and on which a mobile device is placed.