Experiments using a material with single chemical structure, polyethylene (PE), were performed to study the decay process of charge on a polymer surface accumulated by corona discharge. The motion of charge accumulated on a PE surface within a short time period was studied. Experimental results are discussed in relation to theoretical calculations. A new experimental apparatus was used. It is concluded from the observed charging time dependence of the potential decay that the accumulated charge with a short charging time moves along the surface as well as in the bulk while that with a long charging time moves only in the bulk.