The finite
difference time method is frequently used as a numerical solver for the Maxwell equation and its application.
We present a method to analyze a Finite
Difference Time Domain method. The method is based on
asymptotic analysis approach in connection with standard truncation error. This approaches leads to a consistency analysis, which provides order-by-order information about the numerical solution of the FDTD method. In order to present the basic ideas of the analysis, we will consider a simple one-dimensional FDTD method. The results show that the analysis gave accurate prediction of the solution and can be applied to other analysis such as initial and boundary conditions.