The Satellite Application Facility on Climate Monitoring (CM SAF) is a ground segment of the European Organization for the Exploitation of Meteorological Satellites (EUMETSAT) and one of EUMETSATs Satellite Application Facilities. The CM SAF contributes to the sustainable observing of the climate system by providing essential climate variables related to the energy and water cycle of the atmosphere (< http://www.cmsaf.eu>). It is a joint cooperation of seven National Meteorological and Hydrological Services. The 'cmsaf' R-package provides a collection of R-operators for the analysis and manipulation of CM SAF NetCDF formatted data. The 'cmsaf' R-package is tested for CM SAF NetCDF data, which are structured in three-dimensional arrays (longitude, latitude, time) on a rectangular grid. Layered CM SAF data have to be converted with the provided levbox_mergetime() function. The 'cmsaf' R-package operators have only minor checks for deviations from the recommended data structure, and give only few specific error messages. Scripts for an easy application of the 'cmsaf' package operators and the preparation and visualization of CM SAF NetCDF data are provided at the CM SAF webpage (< http://www.cmsaf.eu/EN/Products/Tools/Tools_node.html>).