A current-to-voltage conversion circuit (4, 4A, 4B, 4C, 4D, 4E, 4F, 4G, 4H, 41, 4J, 4K), comprising: a first resistor (101, 201, 301, 401, 501, 511, 601, 611, 701, 711, 801, 811, 901, 1001, 1101, 1201) including a first end and a second end, the first end of the first resistor being connectable to an electrode included in a sensor, the second end of the first resistor being connected to a first electrical potential, the first resistor being configured to fix, to the first electrical potential, an electrical potential input from the sensor; a first current source (103, 203, 303, 403, 503, 513, 603, 613, 703, 713, 803, 813, 903, 1003, 1103, 1203); a first capacitor (102, 202, 302, 402, 502, 512, 602, 612, 702, 712, 802, 812, 902, 1002, 1102, 1202) including a first end and a second end, the first end of the first capacitor being connected to the first end of the first resistor, the first end of the first capacitor being connectable to the electrode included in the sensor, the second end of the first capacitor being connected to the first current source; a first output terminal (T1, T11, T12); a first voltage source (105, 205, 305, 405, 505, 515, 605, 615, 705, 715, 805, 815, 905, 1005, 1105, 1205); a first transistor (104, 204, 304, 404, 504, 514, 604, 614, 704, 714, 804, 814, 904, 1004, 1104, 1204) including a first terminal, a second terminal, and a control terminal, the first terminal being connected to the second end of the first capacitor, the second terminal being connected to the first output terminal, the control terminal being connected to the first voltage source; and a second resistor (106, 206, 306, 406, 506, 516, 606, 616, 706, 716, 806, 816, 906, 1006, 1106, 1206) including a first end and a second end, the first end of the second resistor being connected to the second terminal, the second end of the second resistor being connected to a second electrical potential. a first resistor (101, 201, 301, 401, 501, 511, 601, 611, 701, 711, 801, 811, 901, 1001, 1101, 1201) including a first end and a second end, the first end of the first resistor being connectable to an electrode included in a sensor, the second end of the first resistor being connected to a first electrical potential, the first resistor being configured to fix, to the first electrical potential, an electrical potential input from the sensor; a first current source (103, 203, 303, 403, 503, 513, 603, 613, 703, 713, 803, 813, 903, 1003, 1103, 1203); a first capacitor (102, 202, 302, 402, 502, 512, 602, 612, 702, 712, 802, 812, 902, 1002, 1102, 1202) including a first end and a second end, the first end of the first capacitor being connected to the first end of the first resistor, the first end of the first capacitor being connectable to the electrode included in the sensor, the second end of the first capacitor being connected to the first current source; a first output terminal (T1, T11, T12); a first voltage source (105, 205, 305, 405, 505, 515, 605, 615, 705, 715, 805, 815, 905, 1005, 1105, 1205); a first transistor (104, 204, 304, 404, 504, 514, 604, 614, 704, 714, 804, 814, 904, 1004, 1104, 1204) including a first terminal, a second terminal, and a control terminal, the first terminal being connected to the second end of the first capacitor, the second terminal being connected to the first output terminal, the control terminal being connected to the first voltage source; and a second resistor (106, 206, 306, 406, 506, 516, 606, 616, 706, 716, 806, 816, 906, 1006, 1106, 1206) including a first end and a second end, the first end of the second resistor being connected to the second terminal, the second end of the second resistor being connected to a second electrical potential.