The invention concerns a measuring apparatus for the detection of foreign
bodies in a product, in particular in tobacco, cotton or some other
fibrous product, having a measuring device, a device for generating an
alternating electromagnetic field in the measuring device, which is
influenced by a product which is arranged in a measuring volume of the
measuring apparatus, a circuit device which includes the measuring device
and which is designed to determine at least one suitable measurable
variable of the alternating field influenced by the product, and an
evaluating device which is designed for detection of the foreign body by
suitable evaluation of the measurable variable determined with the
circuit device, and is distinguished in that the measuring device is a
measuring capacitor and the frequency of the alternating field is in the
high-frequency range below the microwave range. The application further
concerns a corresponding measuring method.