The Semantic Web, also known as the Web of meaning, is considered the new generation of the Web. Its objective is to enable computers and people to work in cooperation. A requisite for this is encoding data in forms that make web contents (meaning, semantics) more understandable by algorithmic means. In this paper, we present the application of Semantic Web concepts and technologies to the access control area. The Semantic Access Control Model (SAC) uses different layers of metadata to take advantage of the semantics of the different components relevant for the access decision. We have developed a practical application of this access control model based on a specific language, denominated Semantic Policy Language (SPL), for the description of access criteria. This work demonstrates how the semantic web concepts and its layers infrastructure may play an important role in many relevant fields, such as the case of access control and authorization fields.