With the increasing popularity of the World Wide Web, the amount of information available and the use of Web servers are growing exponentially. As a consequence, the number of requests to popular Web servers increases exponentially as well. In order to reduce the overhead induced by frequent requests to the same documents, server caching, also referred to as main memory caching, has been proposed and implemented. In this work, we propose a static caching mechanism which consists of updating the contents of the cache periodically and, at the update time, brings into the cache only the most requested documents in the previous time interval. This caching policy has lower management overhead than others. Under some statistical assumptions we show that static caching has the highest hit rate. We also provide empirical comparison results obtained by trace-driven simulations. It turns out that static caching is more efficient in terms of hit rate than those analyzed in the literature.