Most solids emit low-level seismic signals known as acoustic emission/microseismic (AE/MS) activity. In recent years AE/MS techniques have been utilized for stability monitoring of underground structures such as mines, tunnels, natural gas and petroleum storage caverns, radioactive waste repositories, and geothermal reservoirs, as well as surface structures such as foundations, rock and soil slopes, bridge piers and abutments, and dams. This study includes details on AE/MS related topics such as basic material behaviour, stress wave propagation, transducer design and installation, electronic in.