1. A method of controlling a mobile terminal comprising: displaying, on a display of the mobile terminal, at least one first object on a perceived three-dimensional (3D) space having at least a first layer and a second layer, wherein the first layer is a topmost layer of the 3D space, the third layer is a bottommost layer of the 3D space, and the second layer is between the first layer and the third layer, wherein the first layer has a 3D level of a first depth and the second layer has a 3D level of a second depth, and wherein the at least one first object is arranged on the first layer provided at a reference depth; receiving a user input for selecting one of the at least one first object at the mobile terminal while displaying the at least one first object on the first layer provided at the reference depth; automatically arranging at least one second object on the second layer when the 3D level of the second layer changes to the first depth and the second layer is provided at the reference depth; changing the 3D level of the first layer from the first depth to the third depth by changing a visual characteristic of the first layer, wherein the visual characteristic is a translucency of an object displayed on the first layer; and displaying the at least one second object on the second level of the display, as the 3D level of the first layer changes from the first depth to the third depth, automatically varying a translucency of the at least one second object on the second layer as the second layer is provided at the reference depth, wherein the first layer becomes translucent as the first layer is removed from the reference depth and is provided at another depth such that the at least one second object on the second layer provided at the reference depth can be seen through the first layer, and wherein each of the at least one second object corresponds to a sub-menu of a menu corresponding to the selected one of the at least one first object, wherein the first layer and the second layer are planar layers, and the first layer and the second layer are parallel to each other, wherein the first depth is perceived to be seen closer to a user than the second depth, and the second depth is perceived to be seen closer to the user than the third depth, and wherein the display displays the perceived 3D space in a stereoscopic manner.