In the paper a scenario of an electromagnetic response formation from the merging of two black holes is considered. In this scenario it's assumed that the binary black hole is surrounded by an accretion disk. As a result of the black holes merging and mass loss, the accretion disk experiences a disturbance, which is accompanied by shock waves propagation of sufficiently high intensity. Heating of matter by shock waves leads to a sharp increase in the flux of electromagnetic radiation from the disk. The paper includes a calculated light curve, radiation spectrum, and the estimation of characteristic duration of the flare. This method can be used to discover of electromagnetic responses from gravitational-wave events, which registered by the LIGO (Laser Interferometer Gravitational-Wave Observatory) and the Virgo detectors. Supporting the registration of gravitational-wave events by observations in the electromagnetic channel has far-reaching prospects, since it corresponds to the multi-messenger approach to the study of astrophysical objects.