The commands that can be used in a recording device can be changed without changing the firmware. A printer 2 that operates and records according to commands received from a host computer 4 has a plurality of built in commands, including a command related to a specific language, and stores command configuration data 24C setting the executability of each command. The printer 2 can operate in a plurality of operating modes including a normal operating mode and a setup configuration mode, moves to the configuration mode when a specific control command is received from the host computer 4, and changes the command configuration data 24C according to the configuration command when a configuration command for changing settings in the command configuration data 24C is received while in the configuration mode.