  We synthesized the samples Sr$_{1-x}$Sm$_x$FFeAs with ZrCuSiAs-type
structure. These samples were characterized by resistivity and susceptibility.
It is found that substitution of rare earth metal for alkaline earth metal in
this system suppresses the anomaly in resistivity and induces
superconductivity. Superconductivity at 56 K in nominal composition
Sr$_{0.5}$Sm$_{0.5}$FFeAs is realized, indicating that the superconducting
transition temperatures in the iron arsenide fluorides can reach as high as
that in oxypnictides with the same structure.
