We have developed a simulation algorithm of carrier transport subject to Lorentz force in semiconductor films. The Lorentz current is discretized with the drift and diffusion currents, and the simulation algorithm is implemented in finite difference methods. Hall effect around a grain boundary in a polycrystalline semiconductor film is evaluated as a simulation example, and it is found that a high Hall voltage is generated at the grain boundary. (C) 2011 Elsevier Ltd. All rights reserved.