The use of integrated circuits (ICs) is continually increasing in any kind of industrial products and in particular in the electronic and information and communications technology products. The environmental impact related to the use and production phases of the ICs could be potentially very strong due to the high technological level of the process, the amount of energy and the special materials used for their realization. The aim of this study is to evaluate the environmental impact of an IC during its production and use phases basing on the life cycle assessment (LCA) methodology. In fact the LCA is a useful tool to quantify the environmental impact. An EPROM IC has been chosen as a representative device for its technological complexity and its large diffusion in the market. Front-end and back-end technological steps have been analyzed in detail. The energy and the fixed consumables (gases, chemicals, ...,) used in the fab have been related to the number of masks. The number of the masking steps is an indicator of process complexity, The data inventory has been obtained from detailed technological analysis, from information obtained directly from material suppliers and from the commercial database. The IC process makes large use of de-ionized water (DI). The reclaim of DI water and other materials is important in order to reduce the total environmental impact. The total inventory for a single EPROM chip has been obtained. The same approach can be extended to other types of ICs.