The information processing system includes an arithmetic processing unit, a master control unit including a master memory, and slave control units each including a slave memory. The master control unit stores in a master memory transmission data including address information that can designate the address of any one of the master memory and the slave memory, which is sent from the arithmetic processing unit, or transmits the transmission data to the corresponding slave memory via a communication data memory. Such the information processing system can reduce the number of times of directions from the master control unit to the slave control unit.