In an image forming apparatus connected to a network, an interface unit receives information requesting data via the network and transmits response data to the network during a normal mode and a standby mode. A storage unit stores the response data being read out during the standby mode. A normal-mode response data generating unit generates the response data during the normal mode. An information storing unit, during the normal mode, stores, in the storage unit, information about the response data. A standby-mode response data generating unit, during the standby mode, generates the response data from the information about the response data, and stores a response frequency of the information. A stored response data deleting unit deletes, if an amount of the information exceeds a storage capacity of the storage unit, the information with the response frequency that is lower than a specified threshold.