Apparatus and method for detection of vehicles

An apparatus and a method for detecting vehicles are provided to reduce maintenance and installation cost and to measure a traffic volume in many sections by installing the detecting apparatus at roads or parking lots through a compact size. An apparatus for detecting vehicles includes a sensing unit(210), a calculating unit(220), a wireless communication unit(230), and a power supply unit(240). The sensing unit detects the variation of magnetic field. The calculating unit determines whether vehicles exist or not based on the variation of the magnetic field. The wireless communication unit transmits data which represents the existence of the vehicles, to a traffic information collecting unit. The power supply unit supplies an electric power to the calculating unit and the wireless communication unit based on whether or not the variation of magnetic field is varied.