Diffraction of the E-polarized electromagnetic wave by a semiinfinite strip grating is considered. The scattered field is represented as a superposition of the field induced by the currents on the strips of an infinite periodic grating and the field induced by the correction current excited due to end of the grating. A singular integral equation with additional conditions for correction current density is obtained. A solution for the infinite periodic grating in the E-polarization case is obtained from the corresponding solution for the H-polarization case using the duality principle. Numerical results for the current density and far fields distribution are represented.