To provide a sampler in the ground capable of efficiently and accurately investigating a state of contamination.

The sampler 1 in the ground approximately comprises a hollow cylindrical boring pipe 2 and a sampling attachment 3 provided to the front end on an excavation side of the hollow cylindrical boring pipe. The hollow cylindrical boring pipe 2 is constituted that a pair of first boring bits 4 and 4 are provided to the outer circumferential surface in the vicinity of the front end on the excavation side and, at the same time, that a spiral vane 5 necessary to drive into the ground is wound on the outer circumferential surface. A sampling sample holding bag 11 is inserted inside of a hollow of the hollow cylindrical boring pipe 2. The sampling attachment 3 comprises a cylindrical body 13 fitted inside of the hollow of the hollow cylindrical boring pipe 2, a collar-like connecting section 14 projected to the circumferential edge of the end section of the cylindrical body and a pair of second boring bits 12 and 12 provided to the end section on the excavation side of the cylindrical body 13 and the end face on the excavation side of the collar-like connecting section 14.