This Technical Report specifies a method for the determination of the content of silicon in steel by means of inductively coupled plasma emission spectrometry. This method is applicable to silicon contents of mass fraction 0,02 % to 5 %. The method uses a calibration based on a very close matrix matching of the calibration solutions to the sample and close bracketing of the contents around the approximate concentration of silicon in the sample to be analysed. The concentrations of all elements in the sample has, therefore, to be approximately known. If the concentrations are not known the sample has to be analysed by some semi-quantitative method. The advantage with this procedure is that all possible interferences from the matrix will be automatically compensated, which will result in high accuracy. This is most important for spectral interferences, which can be severe in very high alloys. However, all possible interferences have to be kept to a minimum. Therefore it is essential that the spectrometer used, meet the performance criteria specified in the method for the selected analytical lines.