This work summarizes the state-of-the-art development of inertial electrostatic confinement (IEC) thruster, which can be divided into two parallel lines of development: the IEC plasma source and the corresponding electromagnetic nozzle (EMN). Both developing lines start from the establishment of the theory and modeling and evolve to the design implementation and experimental verification. The IEC discharge model highlights a novel perspective on the IEC discharge physics and the impacts of the respective critical parameters, which layouts the design for the IEC plasma source. Experimental verification for the theory is demonstrated via the optical emission spectroscopy and collision radiative model. The results provide conclusive evidence of forming a spherical double layer within the IEC plasma source, which is the key to establishing the proposed IEC discharge theory in this work. This work presents a comprehensive study on the magnetohydrodynamic theory for assessing the plasma acceleration in the magnetic nozzle. Nevertheless, the result shows a performance limitation of the magnetic nozzle. An innovative invention is proposed to overcome the limitation known as the EMN. Thorough descriptions of EMN and its working principle are summarized in this work, including its effects on plasma confinement, acceleration, and detachment. Investigation of the plasma plume properties by miscellaneous plasma diagnostics tools further demonstrates EMN functionality and constitutes the first IECT prototype with proof-of-concept in literature.