|A micro detector includes a substrate, a fin structure, a floating gate, a sensing gate, a reading gate and an antenna layer. The fin structure is located on the substrate. The floating gate is located on the substrate, and the floating gate is vertically and crossly arranged with the fin structure. The sensing gate is located at one side of the fin structure. The reading gate is located at the other side of the fin structure. The antenna layer is located on the sensing gate and is connected with the sensing gate. An induced charge is generated when the antenna layer is contacted with an external energy source, and the induced charge is stored in the floating gate.