Eight major elements (Al, Fe, Mg, Ca, K, Ti, Mn) and several minor elements (Sc, V, Cr, Co, La) in the artifacts made of clay can be determined by instrumental neutron activation analysis using a thermal neutron flux 10₁₂n/cm₂.s. The authors established a set of irradiation and measurement conditions and checked the procedure by analyzing two geochemical reference samples. Results obtained with the two samples showed agreement.