This Technical Report gives guidance on the measurement of elemental carbon (EC) and organic carbon (OC) following the requirement for the networks of all EU member countries to measure EC and OC in particulate matter from June 2010 at background sites according to the Council Directive 2008/50/EC on ambient air quality and cleaner air for Europe. The Technical Report describes the analytical procedures for determining EC and OC on quartz fibre filters as μg/cm2, and the subsequent calculation of concentrations as μg/m³. Sampling onto filters is to be done in accordance with EN 14907 for PM2,5. The sampling process determines the size fraction of the particulate matter, the retention of semi-volatile material, and ab/desorption of volatile organic compounds on the filter at the time of sampling. The same analysis method may also be used for other size fractions. Any possible additional artefacts e.g. due to charring or higher concentrations of carbonates would need to be assessed in those cases.