To provide an FIR(Finite Impulse Response) filter that can prevent equality of ripples from being deformed due to a weight approximation error and can keep a gain of a pass band to be nearly constant and to provide a method for setting its coefficient. 重みつき近似誤差の等リプルの崩れを防止でき、また通過域の利得を略一定値に保持できるFIRフィルタおよびその係数の設定方法を提供する。 - 特許庁