An image forming apparatus provided by the present invention can suppress communication congestion between controllers. In the image forming apparatus, statuses ST (i) is read from a queue in turn (Step S0), an address content corresponding to status ID=ST(i).ID in a first status storage unit is updated by using status value ST(i).V (Step S1); when a status ID dependent on ST(i).ID exists in ST(0)-ST(N-1) received in the same period in the form of ST(j).ID (Step S5), and the address contents (status values) in the first and second status storage units corresponding to the ST(j).ID are different (Step S7), the status ST(j) is notified prior to the status ST(i) (Step S8, S10), and the corresponding content in the second status storage unit is updated by using the statuses ST(j) and ST(i) (Step S9, S11).