To support a contributor to trace how collected contributions are spent.

A server 1 determines a contribution collection ID for each day of collecting the contributions on the street and sends it to a contribution collection promotion group 6 before contribution collection on the street (1). When the contributor 10 contributes money (2), the contribution collection ID is notified (3). The group 6 sums up the amount of the collected contributions for each contribution collection day, transmits it together with the contribution collection ID as collected contribution reception data (4) and transmits data including a used money amount, a supporting object region, a supporting execution date, uses and supporting introduction information, etc., as supporting execution data every time supporting is performed further (5). The server 1 decides a supporting ID for the supporting execution data and makes the supporting ID correspond to one of the contribution collection IDs according to a predetermined correspondence rule. When the contributor notifies the contribution collection ID to a tracing information providing server 3 by using an information terminal 11 later (6), tracing information including the explanation sentence of the use of the collected contribution used in the supporting of the supporting ID made to correspond to the contribution collection ID of the contributor is displayed at the information terminal 11 (7).