A loop heat pipe includes an evaporator, a liquid seal container and a closed loop. The evaporator includes an evaporator body made of a heat conductive material. The evaporator body includes at least two retaining holes and at least a channel hole penetrating the retaining holes. The liquid seal container is secured fastened to one of the retaining holes of the evaporator. A capillary structure is adhered to the inner wall of the liquid seal container. One end of the liquid seal container forms a liquid seal region using the capillary structure. The closed loop includes at least two closed ends. One of the closed ends is securely fastened to the other retaining hole of the evaporator, while the other closed end is communicably connected to the liquid seal region of the liquid seal container.