A digital-to-analog converter (DAC) and a digital-to-analog converting method are provided. The DAC includes a first capacitor, an operation amplifier having a first input terminal connected to the first capacitor, a second input terminal, and an output terminal, where the first input terminal is a (-) input terminal and the second input terminal is a (+) input terminal; and a switching circuit having a plurality of switches each being switched in response to a corresponding switching signal from among a plurality of switching signals. The switching circuit performs switching so that the difference between a first voltage and a second voltage can be stored in the first capacitor connected to the operation amplifier during a first period, and performs switching so that an output signal can be output by reflecting a third voltage in the difference stored in the first capacitor during a second period.