The VOCs discharge characteristics of miscellaneous assembly metal manufacture & metal processing industries, in the SihwaㆍBanwol Industrial Complex, were analyzed according to detailed categories per industry, as based on the Korea Standard Industrial Classification, by comparing the conditions before and after the installation of process and prevention facilities. The average concentration of benzene was highest in the metal heat treatment industry (28921) whereas that of toluene was highest in the painting & membrane treatment industry (28923). In addition, with respect to prevention facilities, our evaluation proved that the decreased efficiency was worse for the discharge facilities of pollutants from the plating industry (28922) and painting & miscellaneous membrane treatment industry (28923), with some exceptions, while most facilities showed no decreased efficiency. Therefore, it is believed that an accurate survey of the conditions of administration/operation facilities will need to be conducted, and the decreased efficiency will also need to be evaluated so that adequate prevention facilities can be reviewed and selected.