The invention relates to an input impedance boosting device. The input impedance boosting device comprises an analog-to-digital conversion circuit; an input capacitor connected to an input terminal of the analog-to-digital conversion circuit and a ground line, and having a first shield metal formed on a lower portion thereof; a feedback capacitor, which is connected to a positive feedback loop of the analog-to-digital conversion circuit, and which has a second shield metal formed on the lower portion thereof; and an impedance boosting part connected to both ends of the feedback capacitor and boosting the input impedance based on a first parasitic component formed between the input capacitor and the first shield metal and a second parasitic component formed between the feedback capacitor and the second shield metal.
