  Globular clusters have been alternatively predicted to host intermediate-mass
black holes (IMBHs) or nearly impossible to form and retain them in their
centres. Over the last decade enough theoretical and observational evidence
have accumulated to believe that many galactic globular clusters may host IMBHs
in the centres, just like galaxies do. The well-established correlations for
supermassive black holes and their galaxies do suggest that, in extrapolation,
globular clusters (GCs) follow the same relations. Most of the attempts in
search of the central black holes (BHs) are not direct and present enormous
observational difficulties due to the crowding of stars in the GC cores. Here
we propose a new method of detection of the central BH--the microlensing of the
cluster stars by the central black hole. If the core of the cluster is
resolved, the direct determination of the lensing curve and lensing system
parameters is possible; if unresolved, the differential imaging technique (or
pixel lensing) can be applied. We calculate the optical depth to central BH
microlensing for a selected list of Galactic globular clusters and estimate the
average time duration of the events. We present the observational strategy and
discuss the detectability of the microlensing event using a 2-m class
telescope.
