The book contains thorough and complete analytical calculation leading to two transcendental equations satisfied by transverse wavevector dependent confined energy levels of the semiconductor nanostructure called isolated Quantum Well (QW). The book also contains thorough numerical calculation to bring out effects of the non-zero component of wavevector of electron parallel to interfaces of QW on parametric dependence of the confined energy levels. Complete explanations are presented of the results of numerical investigations using a transverse wavevector dependent effective potential. ...