Detection of contained metal contained in an article can be carried out with a high sensitivity with a simple operation in a limited space. A transmission coil 42 that generates a magnetic field for inspection from an upper surface side through a lower surface side of a placing table 21 and a plurality of magnetic sensors 43 for detecting the magnetic field are provided in a head 40 disposed on a lower surface side of the placing table 21 for placing an article which is an inspection object. When the head 40 is scanned so as to cover the entire lower surface-side region of the placing table 21, metal being contained in the article placed on the placing table 21 is detected on the basis of a change in the magnetic field being detected by the magnetic sensors 43.