This study was performed to investigate the problems of using asbestos for dental technicians. Samples for analyzing were sampled by personal sampler in 40 sampling points of 10 dental laboratories in Daegu city from December, 2003 to February, 2004 and counted with phase contrast microscopy. The results were as follows: 1. Asbestos concentration(geometric mean) of 40 sampling points in 10 dental laboratories was 0.0061 f/cc and it was under recommended industrial and indoor air standard, but the concentration of asbestos in only two dental laboratories was over indoor recommended standard. 2. The concentration of asbestos in processing room and burnout room was 0.0099 f/cc and 0.0037 f/cc, respectively. 3. The mean concentration(GM) of asbestos by kinds of casting ring liners was 0.0159 f/cc in dental laboratories using industrial asbestos, 0.0104 f/cc in them using asbestos containing ring liners, and 0.0026 f/cc in them using non-asbestos ring liners. Casting ring liners using in dental laboratories should be substituted with non-asbestos liners, because most of dental laboratories were using asbestos containing ring liners and a few of them showed higher concentration than recommended standard.