A communication apparatus comprising: a first power supply configured to generate first power; an antenna configured to perform non-contact communication with an external device; a second power supply configured to generate second power based on electric power supplied from the external device via the antenna, the second power being less than the first power; a communication controller configured to control non-contact communication with the external device via the antenna while at least one of the first power and the second power is supplied to the communication controller; a main controller configured to control the communication apparatus to perform a function thereof while the first power is supplied to the main controller; a communication node configured to operate while at least one of the first power and the second power is supplied to the communication node, the communication node having a power input port; a first supply route that electrically connects the first power supply to the power input port of the communication node; and a second supply route that electrically connects the second power supply to the power input port of the communication node, a first electrical component provided on the first supply route and configured to prevent the second power from being supplied to a particular target electrically connected to the first power supply while the second power is supplied to the communication node, the particular target being different from the communication node; wherein the communication controller is configured to communicate with the communication node in a certain data communication method while the second power is supplied to the communication node; and wherein the second power supply is configured, in response to reception of electric power from the external device via the antenna, to supply the second power to the communication controller, and to supply the second power to the communication node through the second supply route. a first power supply configured to generate first power; an antenna configured to perform non-contact communication with an external device; a second power supply configured to generate second power based on electric power supplied from the external device via the antenna, the second power being less than the first power; a communication controller configured to control non-contact communication with the external device via the antenna while at least one of the first power and the second power is supplied to the communication controller; a main controller configured to control the communication apparatus to perform a function thereof while the first power is supplied to the main controller; a communication node configured to operate while at least one of the first power and the second power is supplied to the communication node, the communication node having a power input port; a first supply route that electrically connects the first power supply to the power input port of the communication node; and a second supply route that electrically connects the second power supply to the power input port of the communication node, a first electrical component provided on the first supply route and configured to prevent the second power from being supplied to a particular target electrically connected to the first power supply while the second power is supplied to the communication node, the particular target being different from the communication node; wherein the communication controller is configured to communicate with the communication node in a certain data communication method while the second power is supplied to the communication node; and wherein the second power supply is configured, in response to reception of electric power from the external device via the antenna, to supply the second power to the communication controller, and to supply the second power to the communication node through the second supply route.