In this article, we present PREMIS OWL. This is a semantic formalisation of the PREMIS 2.2 data dictionary of the Library of Congress. PREMIS 2.2 are metadata implementation guidelines for digitally archiving information for the long term. Nowadays, the need for digital preservation is growing. A lot of the digital information produced merely a decade ago is in danger of getting lost as technologies are changing and getting obsolete. This also threatens a lot of information from heritage institutions. PREMIS OWL is a semantic long-term preservation schema. Preservation metadata are actually a mixture of provenance information, technical information on the digital objects to be preserved and rights information. PREMIS OWL is an OWL schema that can be used as data model supporting digital archives. It can be used for dissemination of the preservation metadata as Linked Open Data on the Web and, at the same time, for supporting semantic web technologies in the preservation processes. The model incorporates 24 preservation vocabularies, published by the LOC as SKOS vocabularies. Via these vocabularies, PREMIS descriptions from different institutions become highly interoperable. The schema is approved and now managed by the Library of Congress. The PREMIS OWL schema is published at http://www.loc.gov/premis/rdf/v1.