An electricity meter capable of minimizing a risk of data destruction in case of lightning or surge that involves improperly high voltage is provided. The electricity meter includes a measurement part, an operation part, and an insulation part. The measurement part includes a detection unit to detect electricity consumption of an objective system and a transmission unit to wirelessly transmit data representative of the detected electricity consumption. The operation part includes a reception unit to receive the wirelessly transmitted data and an operation unit to process the received data into data representative of electric energy consumed by the objective system. The insulation part electrically insulates the measurement part and operation part from each other.