An image forming apparatus comprising: a. a communication means to communicate with a portable information device; b. an operation accepting means to accept an operation by a user; c. an operation state switching means adapted to monitor an input to said operation accepting means and to switch an operation state between an operating state showing a state in which a user is inputting an operation to said operation accepting means and a non-operating state that is not said operating state; d. a display means to display an image; e. an operation screen transmission means to, in response to a request being received from said portable information device when an operation state is being switched to said non-operating state, transmit an operation screen corresponding to said received request to said portable information device through said communication means; and f1. a communication state switching means adapted to monitor a communication state of the communication means and to switch a communication state between a communicating state indicating a state in which a user is inputting an operation to said portable information device and a non-communicating state that is not said communicating state, wherein f2. when said communication state is said communicating state, in which a user is inputting an operation to said portable information device, an operation input to said operation accepting means is disabled; and f3. when said operation state is said operating state showing a state in which a user is inputting an operation to said operation accepting means, an operation input from the portable information device is disabled; and characterized by g. a display control means configured to, in response to transmission of said operation screen, display an image of a help screen for assisting in inputting in accordance with said operation screen on said display means. a. a communication means to communicate with a portable information device; b. an operation accepting means to accept an operation by a user; c. an operation state switching means adapted to monitor an input to said operation accepting means and to switch an operation state between an operating state showing a state in which a user is inputting an operation to said operation accepting means and a non-operating state that is not said operating state; d. a display means to display an image; e. an operation screen transmission means to, in response to a request being received from said portable information device when an operation state is being switched to said non-operating state, transmit an operation screen corresponding to said received request to said portable information device through said communication means; and f1. a communication state switching means adapted to monitor a communication state of the communication means and to switch a communication state between a communicating state indicating a state in which a user is inputting an operation to said portable information device and a non-communicating state that is not said communicating state, wherein f2. when said communication state is said communicating state, in which a user is inputting an operation to said portable information device, an operation input to said operation accepting means is disabled; and f3. when said operation state is said operating state showing a state in which a user is inputting an operation to said operation accepting means, an operation input from the portable information device is disabled; and characterized by g. a display control means configured to, in response to transmission of said operation screen, display an image of a help screen for assisting in inputting in accordance with said operation screen on said display means.