A device for long term sensing and recording electrocardiogram includes a housing body, electrodes, a processing circuit, a water-proof film and at least one flexible attach layer. The housing body includes an upper body and a lower body sealed to form an internal space for enclosing the processing circuit. The middle portion of the water-proof film is sandwiched between the upper body and the lower body, and the outer portion of the water-proof film is attached to a person's skin to form a water-proof region. The flexible attach layer is beneath the water-proof film, and the electrodes penetrate the housing body to electrically connect the processing circuit. The electrodes sense electrocardiogram information, which is processed and recorded by the processing circuit. The device is suitable to wear for a long term without any interference such that the user does not feel uncomfortable even during showering, exercising or sleeping.
