In recent years, a ground sinkhole sometimes occurs due to an underground cavity, and early detection of cavities in the ground that will cause sinkholes is indispensable as a countermeasure. However, non-destructive exploration techniques such as ground-penetrating radar used today are insufficient for detecting subsurface cavities in terms of exploration depth. Methods for subsurface exploration at depths of several to several tens of meters have not yet been established, one of the possible effective methods for detecting cavities in the ground is the use of elastic waves, especially horizontal shear (SH) waves, and the propagation of SH waves around cavities in the ground are observed at the ground surface in numerical analysis using DEM. In this study, laboratory tests were conducted using a model ground and field tests in the actual ground to establish a method for detecting cavities in the ground using seismic waves. In the laboratory test, a model ground within reflective objects such as cavities were made, and the changes of SH waves propagation depending on the position and shape of the model ground were discussed. In the field test, an artificial cavity was created in the ground, and the detection of reflected waves around the cavity and the identification of the depth and shape of the cavity were attempted from the data of excitation and reception in the SH direction.