An electronic money holding device has a first storage unit for storing a
uniquely assigned identification number and an amount of held electronic
money, a processor for controlling the reference to and the updating of
the amount of held electronic money and the transfer of electronic money
between the electronic money holding device and another electronic money
holding device, and a second storage unit for storing information of
service providers concluding sales contracts with a possessor of the
electronic money holding device and payment information of each sales
contract.