Abstract: A seismoscopic detector has a front casing, a rear casing, a positioning plate, a cup and a flashlight. An upper opening, a window, a positioning hole and a plurality of threaded holes are on the front casing. The rear casing has four side plates to support a positioning plate. The inner surface of the side plates has lobes with threaded holes. A cell chamber and a buzzer are disposed in the rear casing. The positioning plate has through holes. A slot and an elastic plate are formed on the positioning plate. The slot is covered by a cell cover. An upper clamp plate and a lower clamp plate are at the lower portions of the positioning plate perpendicularly. A recess and two opposite clipping blocks are formed on the upper clamp plate. A spring is disposed between two clipping blocks. A cup is disposed between two clamp plates. An inner flange is on the cup to receive a sound sensor. A steel ball is placed in the cup. A flashlight is disposed on the spring.