This article highlights a 5-steps methodological framework for evaluating the available marine areas for the installation of offshore wind farms. Furthermore, the study area of our work is the island of Crete, the biggest and most populous island of Greece. The selected area has unique characteristics and great offshore wind potential. Subsequently, the exclusion and the evaluation criteria are selected in terms of the national and European legislation and according to the study area's characteristics. After that, the evaluation criteria are assessed, through the process of personal interviews and questionnaires, from different groups of stakeholders, and then the AHP method is implemented in order to produce the relative importance of the criteria. Finally, all exclusion criteria are performed to a unique layer of GIS and the combination emerged constitutes the exclusion map. However, the evaluation criteria are classified to scale from 1 to 5 (5 the higher suitability) and a layer for each criterion is also produced and the final evaluation map with a ranking suitability from 1-5. Eventually, the final suitability map is produced by multiplying the exclusion and evaluation map with Raster calculator. This work contains an analysis of 4-criteria evaluation and exclusion at the same time. A more analytic and extensive work employing 14-criteria exclusion and 16-criteria evaluation is ongoing.