Network error display capable of displaying a user's measure intelligibly while making a distinction between an error of the receiving system on the network and an error within a device. An IEEE 1394 signal processing section detects an error of a loop state in an IEEE 1394 network, detects a link state, and detects an error when there is a link for the network or an error when there is no link for the network. A main body processing section stores messages indicating error states and performs display processing on messages stored on the basis of the error state. A display section displays a message for a user.