Shear flow is the most important ingredient governing nonlinear behavior of many types of plasma instability. Electromagnetic effects on shear flow generation have been studied for an electro-magnetic drift wave called resistive drift-Alfvén mode (RDAM) and a global MHD mode called resistive wall mode (RWM). For RDAM it is found that the generated shear flow stabilizes the dominant modes; however, other modes are destabilized. For RWM Maxwell stress due to magnetic fluctuations has a tendency to suppress the poloidal flow near the plasma surface, which gives almost same saturation level, since the shear flow stabilization disappears.