A detection method and detection device of buried metal which are capable of detecting singular points, in horizontal and vertical directions, of metal tubes, telecommunication cables, and electric power cables, or the like buried in the ground. A magnetic field component of the direction of 3 axes of a XYZ axis is detected by two or more magnetic sensors installed in the detectable direction, and detects a magnetic field induced to buried metal. While carrying out synchronous detection of these magnetic field components and calculating for each amplitude and each phase of a magnetic field component of the direction of 3 axes, image processing is carried out and it is outputted to a display. While calculating for the position of a singular point, a singular point distinguishes whether it is an over-crossing state, it is an under-crossing state, or it is a branched state from these image data