An apparatus detecting the position of the functional layer of the electrode plate includes a first electrode plate sensor disposed at a side of a material to sense start points of electrode plates continuously formed on the material at uniform intervals, a second electrode plate sensor disposed at an other side of the material to sense a length of the electrode plate, a functional layer sensor provided behind the first electrode plate sensor and the second electrode plate sensor above a material traveling direction to sense position and length of the functional layer formed on the electrode by sensing a difference in color, and a controller feeding back a feedback result indicating whether the functional layer is correctly coated through values sensed by the first electrode plate sensor, the second electrode plate sensor, and the functional layer sensor.