PROBLEM TO BE SOLVED: To provide an electrocardiographic device capable of accurately measuring an electrocardiogram.SOLUTION: An electrocardiographic device 1 includes a sheet electrode A and a sheet electrode B installed on a sheet of a vehicle a steering electrode 7 installed on a steering of the vehicle a feedback means 25 for feeding a potential between the sheet electrode A and the sheet electrode B back to the steering electrode 7. A differential signal of the sheet electrode A and the sheet electrode B is taken out as an electrocardiographic signal.