Volatile organic compounds (VOC), aldehydes, ketones, phenol, sulfuric compounds, polyaromatic hydrocarbons (PAH) and dioxins were analyzed to investigate the concentrations in the sand mold foundry and also to consider the influence of each working process on the production of odor and harmful compounds. As a result, the concentrations of VOC, aldehydes, ketones, phenol, sulfuric compounds, PAH were 120-270 ppb, 18-84 ppb, 9.5-25 ppb, 0.59-0.91 ppb, 11-35 ppb, and 0.017-0.022 ppb, respectively. The obvious production of dioxins was not recognized. It was suggested that the molding process caused the changing of chemical composition in the air and also increased the dilution ratio required until single component threshold. The odor was composed of a simple odor contributed by a few specific compounds such as sulfuric acid and acetoaldehyde while the complex odor was caused by numerous compounds.