Abstract: 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.