A method was developed for mass neutron-activation analysis (without chemical decomposition) of highpurity silicon. Gamma spectra from samples which were irradiated for 24-48 h in a thermal neutron flux of 1013 n/cm2-sec, and which were held for 24-72h, were obtained with a scintillation detector and multichannel analyzer. The gamma spectra were analyzed on a computer by the least-squares method. The following contaminants were found: Cu, As, Sb, Na, Au, W, and P. © 1968 Consultants Bureau.