This paper is concerned with the scattering of an electromagnetic ( EM) pulse by a perfectly conducting half-plane, moving in a free space. It is assumed that the source signal is a plane wave pulse with its envelope described by a Dirac delta function. The representation for the total field is found, and physical interpretation of the solution is given. This representation, valid for all screen velocities, is then reduced to the case of moderate and low velocities, important for practical applications.