Particulate matter (PM) emission from vehicles is one of the biggest issues in terms of environmental protection and influence to human body. Thus, a variety of measurement technologies have been develop so far. Currently, a gravimetric method is most commonly used in the automotive industry, partially because it is specified in the regulations. This method uses a combination of a dilution tunnel and a filter that collects the PM from the diluted sample gas with subsequent weighting by a micro balance. However, since this technique is a batch measurement, it is impossible to determine at what point of the emissions test the Soot, SOF (Soluble Organic Fraction), and the total PM are emitted. Thus the demand for real-time PM measurement under transient test conditions has increased.A fast response flame ionization detector (fast-FID) has been previously shown to detect hydrocarbon-free soot particles utilizing an area accumulation technique of the spike signals that are observed when the fast-FID is fed with soot particles. In this paper, the new technique to measure the Soot and SOF separately and continuously using the differential FID method is explained.