As a result of studies on ways of simplifying X-ray fluorescence spectroscopy, a new method has emerged which is based on spectrum analysis by means of filters. The proposed technique combines the simplicity of nondispersive systems with the resolution of highly complex dispersive equipment. The way is opened for a wider availability of X-ray fluorescence analysis. Fluorescent radiation from a specimen, excited by means of a radioactive source, is measured after transmission through each member of a sequence of filters consisting of elements of consecutive atomic number. Since this provides, in effect, a scan of the radiation by means of the absorption-edges of the filters, enabling elements to be determined quantitatively, the title “Filterscan” has been proposed for this method. A detailed study of the elements shows the technique to be of wide scope. Disadvantages due to interference in certain cases may be overcome by the use of suitable standards. Advantages of this nondestructive method are that it avoids complex instrumentation, elements of adjacent atomic number can be resolved and no interference effects due to target material can occur. Moreover, source stability is accurately assessable and corrections for lost counts are free from form factor calculations. In addition, the method is exempt from the effects associated with higher diffracted orders. The principle is applicable to solids and liquids, metals, nonmetals, conductors, non-conductors or radioactive specimens. It has been applied to the determination of manganese in aqueous solutions, using a simple prototype instrument, over a concentration range from 0·7 to 21·.0 per cent manganese.