Abstract: A memory for searching information through prefix analysis, in particular for building routing tables for nodes of high speed communication networks, such as Internet network, has a memory element which stores a set of information items each associated with a mask information indicative of the number of significant characters in the respective prefix and with a target information. For the implementation of a search criterion based on the longest prefix match, each cell comprises an information field that provides either an address of a next row for the continuation of a search or an information relating to a target reached, and a pair of flags (GO, TARGET) specifying the contents of the information field.