An image forming apparatus includes: a deciding unit that decides whether in-monitoring assertion information representing is recorded in the information storing unit by another image forming apparatus or not; a recording unit that generates new in-monitoring assertion information; an acquiring unit that acquires information to be an image forming target; and an executing unit that executes an image formation processing. The recording unit decides that the condition of the expiration is satisfied when an expiration date represented by information indicative of the expiration date elapses if the information is included in the in-monitoring assertion information recorded by the another image forming apparatus, and the recording unit does not generate the in-monitoring assertion information and the executing unit does not execute the image formation processing in that case when the predetermined condition of the expiration is not satisfied.