NOVELTY - The method for indirect determination of the purity of silanes and germane, comprises producing a silicon layer or a germanium layer from the silane or germane on a surface by deposition from the gaseous state, and then measuring the specific resistance of the produced layer and concluding from the measured value based on previously determined reference value on the purity of the silane or germane used for the production of the layer. The silane is selected from unsubstituted mono-, di- or trisilanes or the unsubstituted mono-, di- or trigermane.    USE - Method for indirect determination of the purity of silanes and germane useful in semiconductor industry or solar cell industry.    ADVANTAGE - The method ensures accurate and rapid indirect determination of the purity of the silanes and germane with high quality.    DETAILED DESCRIPTION - The method for indirect determination of the purity of silanes and germane, comprises producing a silicon layer or a germanium layer from the silane or germane on a surface by deposition from the gaseous state, and then measuring the specific resistance of the produced layer and concluding from the measured value based on previously determined reference value on the purity of the silane or germane used for the production of the layer. The silane is selected from unsubstituted mono-, di- or trisilanes or the unsubstituted mono-, di- or trigermane or simply, multiply or completely halogen-substituted mono-, di- or trisilanes or simply, multiply or completely halogen-substituted mono-, di- or trigermane. The purity correlates itself to the total amount of the elements of the third main group of the periodic system of the elements on one side and/or the fifth main groups of the periodic system of the elements on the other side including the order to the respective main group. The deposition from the gaseous state takes place by chemical vapor deposition process in the case of determination of the purity of silane on a silicon wafer and in the case of determination of the purity of germane on a germanium wafer. The silicon layer or the germanium layer has a thickness of 5-100 mu m in the case of a doped wafer with a specific resistance value of less than 1000 Omega cm and a thickness of 1-50 mu m in the case of a slightly doped wafer with a specific resistance of greater than 1000 Omega cm. The determination of the purity of silane or germane is repeatedly carried out in the frame of an industrial production and/or filling of the silane or germane in the terms of a continuous monitoring of the purity. The method further includes producing or providing the silane or germane, deriving or removing a suited quantity of the silane or germane, producing the silicon layer or germanium layer from a part of the derived or removed silane or germane quantity by the chemical vapor deposition process on silicon wafer or germanium wafer, measuring the specific resistance on the surface of the produced layer, and assigning the measured specific resistance to a degree of purity without assigning the contaminated elements to one of the main groups of the periodic system of the elements. In the measuring step, a profile of the specific resistance is recorded by repeatedly measuring in different heights of the layer measured from the original wafer surface independent of the height of the layer. In the assigning step, the measured specific resistance value recorded independent of the layer height is assigned to a degree of the purity including an order of the contaminated elements to the third and/or fifth main group of the periodic system of the element. An INDEPENDENT CLAIM is included for a system for industrial production and/or filling of silane or germane.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic view of a production- and filling system for silane or germane.    Production and purification (1)    Supply tank (2)    Filling (3)    Deposition (5)    Combustion system. (7)