Pyrocarbon layers were deposited from methane on planar substrates (pyrolytic boron nitride) at a temperature of 1100 o C and residence times of 0.1, 0.5 and 2.5 s. The depositions were performed in a hot-wall reactor with the substrates oriented parallel to the gas flow. Transmission electron microscopy was applied to study the texture and the structure of the carbon layers on a micrometer and nanometer scale. The texture is influenced by the residence time. An alteration from medium- to high-textured carbon is observed from short to long residence times. The nanostructure of high- and medium-textured pyrocarbon is characterized by domains whose sizes do not generally differ.