  The superconductor-insulator transition (SIT) in regular arrays of Josephson
junctions is studied at low temperatures. Near the transition a Ginzburg-Landau
type action containing the imaginary time is derived. The new feature of this
action is that it contains a gauge field $\Phi $ describing the Coulomb
interaction and changing the standard critical behavior. The solution of
renormalization group (RG) equations derived at zero temperature $T=0$ in the
space dimensionality $d=3$ shows that the SIT is always of the first order. At
finite temperatures, a tricritical point separates the lines of the first and
second order phase transitions. The same conclusion holds for $d=2$ if the
mutual capacitance is larger than the distance between junctions.
