© 2021, Electromagnetics Academy. All rights reserved.—In this article, the diffraction of E-polarized electromagnetic plane waves by a double half-plane structure is taken into account. The shift of the upper half-plane through the horizontal axis for different wavenumber and boundary conditions are considered. On the double half-plane structure, fractional boundary conditions are required on the half-plane surfaces. The half-planes are parallel to each other with a variable shift in distance and location. The formulation of the problem is given where the boundary condition is explained, and the integral equations for each half-plane are obtained by using fractional calculus and Fourier Transform techniques. Then, for numerical calculations, the induced current on each half-plane is expressed as the summation of Laguerre polynomials. This leads to having a system of linear algebraic equations needed to be solved. The numerical results show that the shift and the distance between the half-planes give a very important effect on the field values inside and outside the guiding structure. The results are compared and analyzed with Method of Moment and previous results.