A high-precision .DELTA..SIGMA. modulator reduces nonlinear noise due to the use of a multibit DAC and has little hardware and power consumption. A digital signal is DA converted and fed back to a subtraction circuit supplied with an analog signal. The DAC used in this feedback circuit uses a DAC (DWADAC) that includes a weighted pointer so that input digital signals are supplied in order to a plurality of segment elements that construct the DAC. In this DWADAC, the construction and number of the pointer is set based on the type and order of the filter disposed before the ADC.