A method for excavating a hole and an apparatus therefore are suitable for the operation of excavating a hole used for laying a lateral sewer or mounting pipe, which extends from a main sewer pipe toward the ground surface, on the main sewer pipe. The method comprises the step of rotating a rod about its axis in a space provided in the ground while advancing the rod in the direction of penetrating a wall member defining the space, and the step of utilizing the advanced rod as a guide while excavating a hole in the ground from the tip end of the rod toward the space. The apparatus embodying the method described above comprises a rod propelling machine disposed in a space provided in the ground for rotating a rod about its axis while advancing the rod and a excavating machine utilizing the advanced rod as a guide while excavating a hole in the ground from the tip end of the rod toward the space. The rod propelling machine includes an operating mechanism for rotating the rod about its axis while advancing the rod and a guide mechanism which is placed in front of the operating mechanism for guiding the rod in the direction of penetrating a wall member of the pipe which defines the space.