There is a long tradition in the philosophy of explaining the concept of "meaning" in terms of reference of the thing that our sign signifies. At the latest since Wittgenstein, "meaning" has been explained with the formula "meaning=use," where one distinguishes between how one uses something and for what purpose one uses something. The author shows that this dichotomy between the "how" and the "purpose" of use can be unified. He does this by first investigating the concept of the purpose of use and then reconstructs the "use-how" by means of the concept of "convention." Finally, the author demonstrates how to traditional referential semantics can be justified on the basis of the theory developed here.