To provide a surveying method and device capable of accurately detecting a component material of a ground in a short time.

A part 2 which is to be surveyed of a ground 1 is irradiated with laser light 6 to generate plasma 7 by abrasion, and the component material of the ground at the part 2 is detected by an emission spectral intensity distribution 10 of the plasma 7. A boring hole 3 is opened on the ground 1, and a waveguide 9 is inserted from an inlet of the boring hole 3 to the part 2 in the hole. The part 2 is irradiated with the laser light 6 through the waveguide 9 while the emission of plasma 7 generated at the part 2 is guided into the inlet of the boring hole 3, for detection of the ground component material. For example, contamination of the part 2 is surveyed based on the spectral intensity of the contaminant component in the spectral intensity distribution 10. A spectral intensity distribution 15 of a reference bedrock whose kind is known is acquired, and using the spectral intensity distribution 10 of the part 2 and the spectral intensity distribution 15 of the reference bedrock, the kind of bedrock at the part 2 is surveyed.