In this paper, we propose to develop multi-quantum wells (MQWs) on GaAs/GaAlAs semiconductors, bounded by two substrates of the same GaAs type, in tapered lamellar structure (TLS) by thickness degradation. This process begins with an increase in thickness, followed by a decrease. In this article, we study the proper electronic states of this structure, using the transfer matrix method to perform our calculations and the Fortran program to generate our data. We examine the transmission of electrons through this structure for different variations in parameters such as the thickness of each layer dN, and the barrier height x1. The peculiarity of our system is that the majority of states are found to have energies greater than E > 500 meV, making it suitable for use as a high-energy electron filter. We found that increasing layer thickness and barrier concentration had a very significant effect on the electronic eigenstates that appeared and on their quality factors, which represent an important physical quantity in the electron filtering process. We also noted that the loss of electron energy is due to the increase in thickness, which induces a significant shift of the proper states towards the low-energy level. On the other hand, the increase in concentration induces a shift of the states towards the high-energy level, as a result of the increase in the effective mass of the electrons. We hope these results will be taken into consideration for future applications in electronic filtering devices.