The invention is to provide a method for planishing a sealed end of a pipe body for making a heat pipe. According to a preferred embodiment of the method of the invention, the sealed end of the pipe body is fixed within a female mold. Then, a male mold is inserted into the pipe body. By use of the male mold, the sealed end of the pipe body with respect to the female mold is stamped to form a planished surface at the sealed end of the pipe body. Whereby after the heat pipe is finished, an electronic device is capable of being mounted on the planished surface at the sealed end of the heat pipe.