PURPOSE: To realize the application of HELP information with dependence on functions by transferring the list of command functions to a terminal equipment from a host computer against a HELP command given from a terminal and then transferring the list of commands containing the functions designated by the terminal.

CONSTITUTION: An index file 15 displays the list of commands that can be supplied from a terminal equipment while sorting these commands at every function. A HELP information file 16 stores the HELP information which explains the contents of those commands. A command HELP execution control part 12 receives a HELP command from the terminal equipment and reads the list of command functions out of the file 15 to transfer it to the terminal equipment. Then the part 12 reads out the list of commands including a designated command function to transfer it and then reads the HELP information on a designated command out of the file 16 to transfer it. Thus it is possible to perform the terminal operations while giving a chance even to a beginner operator who is not familiar with command names to utilize the HELP information.