  We adopt a procedure of operational-umbral type to solve the
$(1+1)$-dimensional fractional Fokker-Planck equation in which time fractional
derivative of order $\alpha$ ($0 < \alpha < 1$) is in the Riemann-Liouville
sense. The technique we propose merges well documented operational methods to
solve ordinary FP equation and a redefinition of the time by means of an umbral
operator. We show that the proposed method allows significant progress
including the handling of operator ordering.
