The appearance of the defect mode in the band gap of the one-dimensional photonic crystal with dielectric filling, caused by the volumetric defect of the periodicity of the structure in the presence of conducting nanolayers deposited on insulating substrates, has been studied. Experimental data confirm the results of calculations of amplitude-frequency characteristics performed using the transfer matrix method and demonstrate the appearance of a defect mode in the bandgap in the X-band at certain values of the thickness 100-140 nm and electrical conductivity of conducting nanolayers 7-200 Ω/sq. The distribution of the electric field strength of an electromagnetic wave inside a photonic crystal with introduced conducting nanolayer into a defect has been calculated at the defect mode frequency for different ratios between the longitudinal size of the defect and the wavelength. Taking into account the field strength distribution in the defect layer of a photonic crystal makes it possible to provide both the transparency effect of a photonic crystal with a conducting nanolayer at the defect mode frequency and the effect of the defect mode suppression. The effects of nonreciprocal wave propagation in a photonic crystal associated with changes in the absorption coefficient have been described. It has been established that the degree of the nonreciprocity effect is determined by the level of interaction of the electromagnetic wave with the structure under study. The possibility of achieving high sensitivity to measure conducting structures based on the analysis of the defect mode of a photonic crystal has been noted. Keywords: photonic crystal, conducting nanolayer, defect mode, nonreciprocity.