An image forming apparatus including maintenance function for maintaining the image forming apparatus at a given operating condition includes an operation screen unit. The operation screen unit is useable for conducting maintenance on the image forming apparatus. The maintenance is categorized into a service-maintenance work conductable by a service engineer within service-operation content, and a user-maintenance work conductable by a user within user-allowed-operation content. The operation screen unit includes a user-specific operation screen, with which the user-maintenance work is conductable for adjusting the maintenance function within the user-allowed-operation content. The user-specific operation screen displays the user-allowed-operation content, which is different from the service-operation content.