Electrodes for detecting an electrocardiographic signal are provided as transparent electrodes 10 and 11. A transparent insulating film 12 is coated on the transparent electrode 10 and 11. The electrocardiographic signal is detected through capacitive coupling between a living body and the transparent electrodes 10, 11 . Such an arrangement is effective in preventing moisture, etc, from adhering to the transparent electrodes 10 and 11, thus avoiding deterioration of the transparent electrodes 10 and 11. The transparent electrodes 10 and 11 are arranged in overlapped relation to a display panel 8, whereby a degree of freedom in arrangement of an operating button, etc. can be increased and a size of an electrocardiographic signal detection device 1 can be reduced,
