PURPOSE: To make the speed-up of a processing compatible with the safety of data in a transaction processing system using plural computers connected through a network.

CONSTITUTION: This system is equipped with a first computer 21 which executes a transaction processing, equipped with a history information transmitting part 24 which transmits the history information (a) of a transaction to a network 41, and a response receiving part 25 which receives a response signal from the network 41. Also, the system is equipped with a no-stop type second computer 31 equipped with a history information receiving part 34 which receives the history information of the transaction from the network 41, response transmitting part 35 which transmits the response signal for confirming the reception of the information according to the operation of the history information receiving part 34 to the network 41, and history information managing part 33 which stores and manages the history information (a) received by the history information receiving part 34.