A method for the detection of objects embedded in building structure subgrades such as cable, concrete reinforcing bars, conduit pipe and the like as well as a hand-operated sensor with an adaptive detection threshold operating according to the method, is disclosed. To reduce an over-detection with the adaptation of the detection threshold, a change in the direction of movement of the sensor being guided over the surface area is recorded with respect to an embedded object. The determination of a change in the direction of movement preferably takes place by measuring the sensor acceleration in two directions with respect to the embedded object. Corresponding speeds are computed at least as estimates from the acceleration values in order to generate a conclusion about a reversal of the direction of movement.