We report on resistivity measurements under hydrostatic gas pressure a
nd ambient pressure dc magnetization which reveal that in a layered or
ganic compound kappa-(ET)2Cu[N(CN)2]Cl an insulating magnetic phase an
d superconductivity coexist in a wide pressure region P greater-than-o
r-equal-to 1 bar, and their interplay causes the reentrant superconduc
tivity in zero applied magnetic field.