A network control device including a network controller for transmitting/receiving data through a network and storing received data in a storage and a network processor for processing data stored in the storage is provided with a usage information acquiring section for acquiring usage information indicating usage state of a CPU, a determining section for determining load state of the CPU from the usage information based on a determination condition, and a mode setting section for setting an interrupt mode to the network processor when the determined load state is low and setting a polling mode when the determined load state is high, the network processor processes data stored in the storage when receiving interrupt notification of the network controller during the interrupt mode, deters the interrupt notification of the network controller during the polling mode and processing data stored in the storage at predetermined intervals.