Experiments on the Giotto and the two Vega spacecrafts measured in situ the chemical and isotopic composition of cometary matter in the coma of comet P/Halley. The PIA and PUMA Particle Impact Analyzers returned data on the chemical and, to a limited extent, also on the molecular composition of the dust grains. The Neutral Mass Spectrometer (NMS) measured the molecular composition of the gas phase. From the investigation of the ion population by the Ion Mass Spectrometer (IMS), by the Positive Ion Cluster Composition Analyzer (PICCA) and also by the NMS additional information on less abundant neutral species in the gas phase could be derived. Some of the most striking results obtained are the high abundance of dust particles rich in organic matter (CHON - particles), a high D/H ratio in cometary water, strong isotopic anomalies in the carbon of the dust particles, a low abundance of nitrogen bearing molecules in the gas phase and the presence of a strong extended formaldehyde and associated CO source. The overall chemical composition is solar like except for an underabundance of nitrogen and a strong depletion of the very volatile hydrogen and the light noble gases. The isotopic anomalies observed for cometary D and C establish, that the matter in the cometary nucleus was never equilibrated with the remainder of the solar system and represents, to a large extent, unprocessed interstellar material. The results will be reviewed and compared with some conclusions from remote observations. An additional source for direct information on the composition of matter in cometary nucleii are the interplanetary dust particles (IDPs) collected by high flying aircrafts. It is generally assumed, that the IDPs are asteroidal and cometary debris with a possible additional contribution from Kuiper belt objects. The fragile cluster particles, which desintegrate during the collection in the stratosphere, show very often strong Deuterium enrichements and also substantial excesses of ¹⁵N. A cometary origin of these particles seems likely. Submicron grains, kwnown as GEMS (glass with embedded metal sulfides) have some properties consistent with interstellar amorphous silicate grains.