Routine smoke analyses are mostly conducted with offline GC/MS or HPLC methods. However, tobacco smoke is a highly dynamic and extremely complex mixture of aerosol particles and vapour phase compounds. Recently, on-line sampling methods coupled with time-of-flight mass spectrometry with single photon ionisation (SPI-TOFMS) have proven to be useful to allow puff-resolved detection of many organic smoke constituents in real time. The main advantages of the SPI-TOFMS technique are its soft and sensitive ionisation without fragmentation as well as high time resolutions. It is therefore suited to investigate cigarette smoke formation mechanisms in real dynamic fashion. Most published puff-resolved and/or on-line studies have been carried out on smoke exiting from the cigarette filter. For fundamental understanding of the combustion/pyrolysis processes during smoke generation, it is desirable to analyse these complex reactions directly inside the burning coal and also along the tobacco rod. For this purpose, a microprobe was constructed which can take samples inside the burning coal. The tip of the microprobe has to be temperature-stabile up to ca. 1100 °C and has a sufficiently small thermal mass to minimise any influence on the actual burning process. The entire microprobe and the subsequent transfer line should be heated to ca. 250-300 °C to avoid condensation and blocking. This work will demonstrate a prototype microprobe with a stainless steel tip. Results obtained from this microprobe linked with SPI-TOFMS will be presented to demonstrate the feasibility for puff-resolved online analysis on semi-volatile aromatic, aliphatic species (1,3 butadiene, isoprene, acetone and acetaldehyde) and nicotine inside the burning cigarette. Comparison with mainstream smoke yields using 2R4F reference cigarettes reveals different behaviours that are determined by the analyte's mass, volatility and relative yields.