PURPOSE: To provide a system which enable a sale applicant and a purchase applicant to speedily search for the possibility of dealings when a dealing contract is made on condition that many parties concerned are present and there are brokers handling many kinds of commodities.

CONSTITUTION: This system is equipped with a memory part 2 which stores data regarding commodities to be handled by brokers and a transmitter and receiver 1 through which a sale applicant or purchase applicant communicates with the brokers, and the broker installs a judging mechanism 3, which compares data on an commodity to be sold or purchased that is sent through the transmitter-receiver 1 with the data regarding the commodity that is already stored in the memory part 2, on the sale applicant side or purchase applicant side and when both the data match each other, an output showing that the dealing will be successful to the sale applicant, purchase applicant, or broker through the transmitter-receiver 1.