To add to an ECR, a charge data processing function and a time data processing function which find bill total amounts, discount parking times, bill amounts, etc., of a parking lot by contract stores.

When a discount button 3e of an input device 3 is operated, a CPU 2 carries out discount exit processing; finds a parking time by subtracting entry time stored in an entry management memory 8c from the current time, after confirming that entered vehicle number matches a vehicle number stored in the entry management memory 8c, when the vehicle enters the parking lot; reads the bearing times of the store by vehicle types out of a discount time table 8d by the stores and vehicle types; and adds the calculated parking time to the period total time of the store by vehicle types, in a bill data memory 8e by the stores.