A current-to-voltage conversion circuit according to one aspect of the present invention includes a first resistor, a first current source, a first capacitor, a first output terminal, a first voltage source, a first transistor, and a second resistor. The first resistor includes a first end and a second end. The first end of the first resistor is connectable to an electrode included in a sensor and the second end of the first resistor is connected to a first electrical potential. The first capacitor includes a first end and a second end. The first end of the first capacitor is connected to the first end of the first resistor and the second end of the first capacitor is connected to the first current source. The first transistor includes a first terminal, a second terminal, and a control terminal. The first terminal is connected to the second end of the first capacitor, the second terminal is connected to the first output terminal, and the control terminal is connected to the first voltage source. The second resistor includes a first end connected to the second terminal and a second end connected to a second electrical potential.