This course introduces variable structure control (VSC) theory which is one of the robust control theories. Various basic theorems of VSC will be analyzed in the sliding mode. Expanding the target plant from a second order plant to the n-th order plant, it will be studied how to determine switching conditions and switching vectors. Stability will be analyzed by designing a feedback control loop. By integrating multi-variable structure with optimal control theory and adaptive control theory, the problem of system optimization and the problem of determining coefficients of switching vector in sliding mode will be resolved. Based on those theories, discrete variable structure control (DVSC) will be introduced. Finally, it will be studied how to apply those theories to the control system in robot systems, space aerial planes, satellites, chemical plants, power plants and motors. (Prerequisites: EE581, EE681)