[en] Recombination coefficient of deuterium on a palladium membrane, exposed to a plasma, was experimentally studied. From observation of the transient behavior of permeation and the nuclear reaction analysis, the recombination coefficient, k_u, on the plasma-facing side was found to be 1.5 x 10^-27 exp(-0.48eV/kT)m⁴s^-1. The recombination coefficient, k_d, on the downstream side was also obtained out its temperature dependence was different from k_u. These results suggested two types of the rate-determining process for the recombination phenomena. (author)