The aim of this work is to describe the main phases for the elaboration of a specific algorithm able to define burned areas applying remote sensing technique. This algorithm is been elaborated in ITALSCAR project requested by the Italian department of civil protection and founded by the European Space Agency. This algorithm can be used to identification of burned area bigger than one hectare. The work is based on the Landsat TM/ETM images acquired before and after the most dangerous period for the forest fire in the year. The images are, first of all, corrected and prepared for the following step of the work, then the implementation of the algorithm happens in five different phases. In the final phase the output of the algorithm has been compared and tested with ground true data.