A power information management device configured to be directly or indirectly connected to a communication network (N1, N2), the device comprising: wiring configured to transmit power, a load unit, a power generation unit and a power storage unit being directly or indirectly connectable to the wiring; a power measurement unit; and a power information generation unit configured to generate, on a predetermined period basis, power information, characterised in that identification information is given to the power information management device, the identification information is unique to a registered power user, settlement of power charges being performed on a registered power user basis, the device further comprises a communication unit configured to transmit, to the communication network (N1, N2), the power information having attached therewith the identification information given to the power information management device, the power measurement unit is configured to measure an amount and a direction of the power transmitted through the wiring, the power information represents the amount and the direction of the power measured by the power measurement unit, the communication unit is further configured to receive second power information transmitted from a device different from the power information management device, and the power information management device further comprises an identification information determination unit configured to determine whether or not identification information attached to the second power information received by the communication unit matches the identification information given to the power information management device, wherein if it is determined that the identification information attached to the second power information fails to match the identification information given to the power information management device, the power information generation unit modifies the power information based on the second power information, and the communication unit transmits the modified power information and the second power information to the communication network (N1, N2). wiring configured to transmit power, a load unit, a power generation unit and a power storage unit being directly or indirectly connectable to the wiring; a power measurement unit; and a power information generation unit configured to generate, on a predetermined period basis, power information, characterised in that identification information is given to the power information management device, the identification information is unique to a registered power user, settlement of power charges being performed on a registered power user basis, the device further comprises a communication unit configured to transmit, to the communication network (N1, N2), the power information having attached therewith the identification information given to the power information management device, the power measurement unit is configured to measure an amount and a direction of the power transmitted through the wiring, the power information represents the amount and the direction of the power measured by the power measurement unit, the communication unit is further configured to receive second power information transmitted from a device different from the power information management device, and the power information management device further comprises an identification information determination unit configured to determine whether or not identification information attached to the second power information received by the communication unit matches the identification information given to the power information management device, wherein if it is determined that the identification information attached to the second power information fails to match the identification information given to the power information management device, the power information generation unit modifies the power information based on the second power information, and the communication unit transmits the modified power information and the second power information to the communication network (N1, N2).