To eliminate waste electric power consumption and securely reduce electric power consumption.

An image forming device includes: a state transition section which has a first electric power consumption mode and a second electric power consumption mode requiring a smaller amount of electric power consumption than that in the first electric power consumption mode and performs transition between the first electric power consumption mode and the second electric power consumption mode; a time measurement means for measuring passage of a time; a data processing section processing received data; a data type recording section which records a type of data and a transition time from the first electric power consumption mode to the second electric power consumption mode while associating the type of the data and the transition time with each other. After the transition time associated with the data type has passed after completion of processing of the data in the data processing section, the state transition section makes the transition from the first electric power consumption mode to the second electric power consumption mode.