PROBLEM TO BE SOLVED: To provide a ground exploring method which can carry out exploration three-dimensionally, at a position of ground that is spaced from a single hole, when carrying out a ground exploration using the single hole, and when a boundary surface or the like exists, which can grasp the relative position of the boundary surface or the like, in relation to the single hole. SOLUTION: A oscillation source 4 and a plurality of oscillation receiving devices 2 are inserted in a boring hole H. An on-ground oscillation source 8 is disposed at a position on the ground surrounding the boring hole H. Elastic waves are generated by the oscillation source 4 and the on-ground oscillation source 8, and are received by the oscillation-receiving devices 2. Then, the oscillation source 4 is moved, and elastic waves are generated again by the oscillation source 4 and are received by the oscillation-receiving devices 2. In this way, the exploration of the object ground to be explored G is carried out, based on a result obtained by moving the oscillation source 4 and receiving the elastic waves generated by the oscillation source 4, by using the oscillation-receiving devices 2. COPYRIGHT: (C)2007,JPO&INPIT