To shorten the time required for erasing by erasing all data included in the hierarchy when the checked result of the sum of installment detail data in the respective hierarchies and the sum of transaction data is correct.

A total processing part 11 calculates the total money amount 41 of the details in request data 4. Also, the total money amount 53 of detail data in debt data 5 is calculated. In the case that the totals 41 and 53 match, an erasing part 10 erases the detail in the request data 4 and the detail data in the debt data 5 and sets a flag to the respective detail data. An intermediate total processing part 12 checks intermediate totals 42 and 52 only relating to the data to which the flag is not set and performs erasure for the correct data. In the case that a non-matching intermediate total is present, a subtotal processing part 13 performs the processing of a subtotal.