  The electrical resistance of CeFeAsO$_{1-x}$F$_x$ (x = 0.06 and 0.08) has
been measured in a magnetic field up to 40T. At zero field, the sample with x =
0.06 shows a structural phase transition around T$_S$~100K, followed by a
spin-density-wave (SDW) transition around T$_{SDW}$~30K. For x = 0.08, the
structural phase transition is suppressed down to T$_S$~60K without a clear
anomaly associated with the Fe-SDW transition, and superconductivity shows up
at T$_C$~25K. At lower temperatures, both samples show a clear resistive peak
around T$_N$~4K, which is associated with the antiferromagnetic (AFM)
transition of Ce-4f electrons. Strikingly, zero resistance is recovered upon
further lowering temperature below T$_N$ for x = 0.08. Moreover, we found that
the AFM transition of Ce 4f-electrons at 4K hardly changes with applying a
magnetic field up to 40T, even in the case of x = 0.08, where superconductivity
has been partially suppressed at such a large field.
