This expository softcover book surveys the main concepts and recent advances in multiscale finite element methods. This monograph is intended for the broader audiences including engineers, applied scientists and those who are interested in multiscale simulations. Each chapter of the book starts with a simple introduction and the description of the proposed methods as with motivating examples. Numerical examples demonstrating the significance of the proposed methods are presented in each chapter. Yalchin Efendiev is a professor at Texas A/M University in College Station, Texas and Thomas Hou is a professor at California Institute of Technology in Pasadena, California.