The invention discloses an electric leakage detector. The detector comprises an incomplete circuit composed of an ammeter, a resistor and a power pack in serial connection, the two ends of the circuit are provided with electrodes respectively, an insulated water tank is also included, the electrode at one end of the circuit is connected to a liquid in the insulated water tank, the electrode at the other end is divided into two strands, the two strands are connected with a conductive layer at the two ends of a wire or cable to be detected, and the wire or cable to be detected is placed in the liquid of the insulated water tank. The electric leakage detector can detect whether electric leakage occurs in the wire or cable, a hidden electric leakage trouble of the circuit can be eliminated timely, damage caused by electric leakage is avoided, the circuit stability is improved, and electric energy is saved effectively.