In electronic equipment 1, a limitation level on reading data from a USB flash drive (storage device) 2 is set to a setting section 3 in advance. The USB flash drive 2 ascertains the setting at the setting section 3 when connected to the electronic equipment 1 and limits reading data based on the determined setting. If the limitation level does not match with the condition for permitting data read-out as determined in USB flash drive 2, the USB flash drive 2 prohibits the electronic equipment 1 from reading out data. By executing the processing for limiting data read-out at the side of the USB flash drive 2, unauthorized leakage of data can easily be prevented.