A method for the detection of a specific material in an object (1), especially in a piece of luggage, using electromagnetic beams, whereby the intensities of non-absorbed beams from at least three beam planes (5.1–5.2) in corresponding detector arrays (4.1–4.5) are measured and evaluated, using the following steps according to the invention:
1. generating an at least two-dimensional picture of the object (1) from the measured intensity values;
2. selecting one of the spatial regions displayed in the picture as a basis of the value of a material value, which is determined from intensity measurements, for examination;
3. determining at least one spatial-geometric value in the region to the examined from positional data of a two-dimensional picture and from intensity values using a stored value of a specific, absorption-influenced value of a suspected material.
4. determining, in addition, the corresponding spatial-geometric value solely from three-dimensional geometric values, which are determined from measured intensity values; and
5. comparing, directly or indirectly, values of the spatial-geometric values determined in steps 3 and 4, or values derived therefrom, in order to determine if the suspected material is actually present.