provided is a searching method for acquiring ground information by mounting a resistor on the leading end of a rod and by piercing the ground with the same . the searching method acquires the ground information on the strength and deformation of the ground , by piercing the ground with the resistor including a frustum of circular cone or an arcuate member containing a deficient sectional shape , in which the angle made between the side face of the resistor having blades in the same direction as the piercing direction and the piercing direction is 5 degrees or less upward and outward from the leading end of the resistor thereby to measure a plurality of transverse ground reactions , and by rotating the resistor having the blades at that depth thereby to measure a plurality of ground shearing forces . the main information such as cøe can be determined in the ground search by inserting an apparatus of one kind into the search depth without moving it up and down . thus , an original position ground search can be performed speedily and lightly and applied to various grounds .