Research and development in activation analysis at the Thailand Institute of Nuclear Technology has been carried out over 40 years. The main activation source is from the TRIGA type research reactor TRR1/M1. Average in-core flux is around 1013 n•cm−2•s−1. Experience on the analysis of various kind of samples range from environmental field especially air particulate, ores, rocks and soil for natural resources exploration as well as industrial applications. Elemental composition in silk thread, silk cocoon and silk products from the royal silk project are one of the research work done incorporation with the Queen Sirikit Institute of Sericulture. Food items are also another topic of interest to our research team.