Аннотация: A faint shell-like nebula has been identified as a possible optical counterpart of the radio supernova remnant G73.9 + O.9. The interferometric observations of the nebula in the H(alpha) line have been carried out using Fabry - Perot plates and an image converter with a focus reducing camera on the 125-cm and 60-cm telescopes. The results of our interferometric observations confirm the identification of the SNR's optical emission. The FWHM of the H(alpha) line in the nebula was found to be around 100-120 km/s as compared with 50-100 km/s outside the radio source G73.9+ + 0.9. An upper limit of expansion velocity or the nebula is found to be about 50 km/s. A genetical relation between the hierarchical system of the shells around Cyg OBI and the SNR is possible, being supported by the kinematic distance of about 0,5-2 kpc, as it follows from the mean radial velocity of the nebula v(LSR) = 4 +/- 3 km/s.