PURPOSE: To facilitate owner's control of a laundry system in consideration for the serviceability of the system for customers by performing centralized control using one host computer installed at a distance from a plurality of machines in network and via a means for feeding electricity, and directing permission of operation to a specific machine from the host computer on condition that a process equivalent to a specified charge is done.

CONSTITUTION: A card reader 6 or a coin sensor 7 is checked to see whether or not all of washing machines 5 in network are being used, and when the charge is sufficient to use equipment selected, an operation permission signal is output to an interface board 34 selected by the customer, so that the washing machine 5 can be operated. After electricity is supplied to the washing machine 5 from the control box 1 of a host computer via the circuit block 3a of a special switchboard 3, the customer pushes an automatic power-off switch and then a running signal is fed to the interface board 34 of the host computer via a running signal line 16 and the host computer converts the running signal and transmits it to a command control portion 24 and checks the operating states of the machines in network.