A light transmissive electrocardiographic electrode 19 and a light transmissive insulating film 20 for detecting an electrical signal relating to an electrocardiographic signal through capacitive coupling are disposed above the light emitting elements 8 and 9 and a light receiving element 10 for detecting an optical detection signal relating to a photo-plethysmographic signal. When a user brings a finger into contact with a contact surface 20A of the light transmissive insulating film 20, the electrical signal relating to the electrocardiographic signal is detected by the light transmissive electrocardiographic electrode 19. At the same time, reflected lights of detection lights emitted from the light emitting elements 8 and 9 after being reflected at the users finger are received by the light receiving element 10 to detect an optical detection signal corresponding to the received reflected lights. The electrocardiographic signal is obtained from the electrical signal detected by the light transmissive electrocardiographic electrode 19, etc., and the photo-plethysmographic signal is obtained from the optical detection signal. Biological information is generated based on both the electrocardiographic signal and the photo-plethysmographic signal,