Sponges are very simply built multicellular animals. The sea sponge Petrosia ficiformis (Poiret, 1789) belongs to the class of Demospongiae and can be found along the entire coast of the Mediterranean Sea and Macaronesia. The aim of this diploma thesis was to isolate and analyze the volatile compounds of the sponge P. ficiformis. Extensive research on this topic was not found in the literature. Therefore, an attempt was made to obtain a more complete profile of volatile compounds from this sponge. Volatile compounds of fresh and air-dried P. ficiformis, sampled on Rtina peninsula near the Pag bridge, were obtained by hydrodistillation in a modified Clevenger apparatus and by headspace-solid phase microextraction on two fibers (HS-SPME). The analysis of all samples was performed by coupled gas chromatography - mass spectrometry on an HP-5MS column. A straight-chain saturated aliphatic hydrocarbon, heptadecane (C 17 H 36 ), was identified as the dominant compound on both fibers. Only octan-3-ol had a higher abundance in the fresh sample on DVB/CAR/PDMS fiber. Also, on both fibers in both fresh and air-dried samples, benzene derivatives formed quantitatively important groups with benzaldehyde and benzyl alcohol as the major compounds. In the distillate, the aliphatic compounds are the group with the largest percentages. The compounds with the highest percentage in the fresh sample were oct-1-ene-3-ol and diisobutyl phthalate, while dimethyl trisulfide and indole were the most abundant in the dry sample.