Provided is an apparatus for electronically controllable transmission, and more particularly, an apparatus for electronically controllable transmission, the apparatus capable of shifting gears by moving a shift lever and sensing the magnetic flux density of a magnet, which moves in accordance with the rotation of the shift lever, by using a three-dimensional (3D) hall sensor. The apparatus includes: a shift lever including one end which is connected to a magnet and shifting gears by moving the shift lever; a shift lever body which is connected to the shift lever and is allowing the shift lever to move around shift axis or select axis; and a sensor unit including a 3D sensor which is mounted fixedly in the place intersecting the shift axis and select axis within the shift lever body and can sense the movement of the magnet around an X-axis, a Y-axis and a Z-axis as the magnet moves, wherein the 3D sensor is mounted at a tilted angle for providing at least two of three output signals with linearity.