Disclosed is an image forming apparatus including: a dedicated operation input section having various function keys provided with the image forming apparatus; a connection section to connect an external operation input section having various keys with the image forming apparatus; a memory section to memorize a correspondence information table for each user, in which relationship between the various function keys of the dedicated operation input section and the various keys of the external operation input section is specified; and a control section to control an image forming operation by referring to the correspondence information table for each user memorized in the memory section when an operation input signal is inputted into the control section through the connection section from any of the various keys of the external operation input section.