Removal of Cu impurity from Si surfaces was investigated. Cu impurity on Si surface was contaminated interntionally by dipping into the standard 1ppm CuC$l_2$ chemical solution. The H-plasma treatments were conducted to remove Cu impurity depending on the rf powers, exposure times and remote distances. After these H-plasma treatments, Si surfaces were analyzed by using TXRF(total X-ray reflection fluorescence) and AFM(atomic force microscope). The concentration of Cu which was intentionally contaminated was about $10^{13}$ atoms/c$m^2$ and its surface roughness(root mean square) was around 2.7$AA$. The Cu concentration and surface roughness were imporved after H-plasma cleaning. The Cu comcentration was reduced more than a factor of 10 and its surface roughness showed more than 30% improvement. This removal mechanism was tried to expain by applying the lift-off phenomena accompanied with the removal of a oxide and Cu impurity.