Surface preparation is very important in re-painting of steel structures so as to extend the effective term of corrosion prevention. Though grinding or blasting have been widely used to remove rust and old coating film on steel surface, both these methods have difficulty in completion of rust-removal and cause some problems such as dust scattering, noise, etc. In order to solve these problems, this paper presents the laser cleaning method which instantaneously sublimes/evaporates the rust on the surface of steel structure. The authors investigate the effects and the applicability of laser cleaning using the specimens made by accelerated corrosion method. The test results confirmed that the laser cleaning can remove the rust almost much as using sand blast, and the salt on the surface of steel can also be evaporated as good as the rust. Moreover, this method seems can be applied on wet surface condition because the moisture and water on the surface of steel can also be evaporated.