Radiatively-driven transfer flow perpendicular to a luminous disk is examined
in the relativistic regime of (v/c)2, taking into account the gravity of the
central object. The flow is assumed to be vertical, and the gas pressure as
well as the magnetic field are ignored. Using a velocity-dependent variable
Eddington factor, we can solve the rigorous equations of the relativistic
radiative flow accelerated up to the {\it relativistic} speed. For sufficiently
luminous cases, the flow resembles the case without gravity. For less-luminous
or small initial radius cases, however, the flow velocity decreases due to
gravity. Application to a supercritical accretion disk with mass loss is
briefly discussed.Comment: 7 pages, 5 figure