This book was written, developed, and class tested at AT&T Bell Laboratories over a nine-year period to instruct and train engineers, scientists, and mathematicians on the intelligent use of the finite element method (FEM). It is also appropriate for undergraduate/graduate students with only an intermediate level calculus background. Its treatment of the FEM as a general numerical analysis technique with problem applications to many different fields of engineering and physical science, not just solid mechanics (e.g., elasticity, plasticity, dynamics) differentiates it from the great number of existing books on the subject.