PURPOSE: To obtain an indicating effect for the settlement of the ground by a very simple and low cost structure in which a coupler of an elastic material is slidably held on a plate to measure the subsidence of the ground.

CONSTITUTION: The upper ends of couplers 7 of an elastic material are projected upwards from inlets 4 between entrances provided in a plate 1 forming the through hole 3 of a pipe 2, and the lower ends of the couplers 7 are slidably inserted and held in outlets 6. A hole 16 for measuring the subsidence of the ground is drilled, and the plate 1 coupled with the lower end of the pipe 1 to go down is thrust, together with the pipe 12, through the pipe 2 erected in the hole 16 and is lowered to a given depth. The couplers 7 are pressed downwards by a hammer 15 hung down, the plate 1 so thrust through the side wall of the hole 16 is fixed to the ground 17, the pipe 12 is uncoupled and pulled up, and the plate 1 is embedded with soil. A rope 20 having a magnetic sensor 19 to detect the plate 1 on its tip is hung down with reference to a meter 21 on the pipe 2 and the moving amount of the rope 20 is measured.