This paper describes the cleanliness levels for the manufacturing environment and silicon wafer surface required by International Technology Roadmap for Semiconductors 2003. Concerning the contamination level for particles there is no significant revision from the 2001 version. As for AMCs, the required level of organic contaminants is expressed in terms of C₁₆H₃₄ instead of CH₄. Table 114 of Technology Requirement for Wafer Environmental Contamination Control summarizes the levels of Surface Molecular Contaminants (SMCs) which are the adsorbed amounts of SMCs after 24-hour exposure of wafer to the air in FOUP (Front Opening Unified Pod) , Pod, Mini-environment as well as clean room air. Recent levels of detection limits of various analytical methods are discussed, and the analysis results for both SMCs on silicon wafer exposed to the air in carrier case and the AMCs in the atmosphere are introduced.