Magnetically marked objects, in particular biological objects, such as cells, are continuously detected by moving at least one magnetically marked object in a magnetic field, measuring a local change in the magnetic field caused by the magnetically marked object, generating a signal, in particular a digitized signal, based on the measured local change in the magnetic field, conditioning the generated signal by at least one convolution of the generated signal using a mathematical function, and evaluating the conditioned signal. The evaluation of the signal includes determining extreme values, in particular maximum values, of the signal and comparing the determined extreme values with a threshold value, in particular a predefined threshold value, which, if exceeded, indicates detection of the object.