1. A voice command processing system, for processing a user issued voice command, comprising: registration means for the advance registration of multiple executable commands; acquisition means for obtaining a user issued voice command; determination means for determining which one of said commands registered in said registration means matches said voice command obtained by said acquisition means; and calculation means for, when said determination means ascertains that said voice command does not match any of said registered commands, analyzing said voice command as a sentence, and for calculating for said registered commands and said sentence a similarity.