The image forming apparatus executes controls relating to image formation in a dispersed manner without centralization. A printer part of the image forming apparatus includes a laser module, an image process module, a paper-feed cassette module, a conveyance module, a both-side module, a fixing module, a paper discharge module and a shared data module. Each module stores operation condition information, indicating its operation condition in the shared data module, and executes autonomously a specific operation by referring to operation parameters and the operation condition information indicating the operation conditions of the modules, stored in the shared data module.