It is argued that the physical remains of industry are valuable repositories of information about a crucial phase in the development of modern society, and that there are uniquely archeological lines of inquiry useful in retrieving this information. Two schools of archeology are involved in the study of past industry. One is industrial archeology, which focuses on monuments and technology; the other is historical archeology, which is more closely aligned with the social sciences. The historical development of both approaches is examined to determine what makes them different from, or similar to, one another. Studies of common industrial site types, including potteries, glassworks, iron works, mines, and communities, are reviewed, and research themes and traditions are extracted and analyzed. The essential character of industrial sites is delineated, with particular attention to questions of time, scale, and site content. The industrial site and the practice of industrial archeology are redefined. Appropriate and effective data collection techniques are suggested, key research questions are proposed, and criteria for assessing site significance are examined.