The radial particle flux induced by the fluctuation is measured by a Gold Neutral Beam Probe. Then the transient transport phenomenon induced by the fluctuation is investigated in the tandem mirror GAMMA 10. When the drift wave is excited at the central cell, the density near the center is reduced and the divergence of the flux becomes similar to the time derivative of the electron density. It shows that the density reduction is caused by the flux induced by the drift wave. After the density reduction, the drift wave is saturated and comes to the steady state because the density reduction accompanies the reduction of density gradient. Therefore, the transport phenomenon accompanying the growth and saturation of the drift wave is observed experimentally. In the steady state, the phase difference obeys the boltzman relation including the electron non-adiabatic term.