An information display system according to the present invention includes a head-mounted unit having a see-through information display portion displaying images so that the images can be observed as virtual images, a first transmitter-receiver for receiving a power supply instruction signal for supplying electric power from a main unit by radio, and a first power supply circuit including a battery for supplying electric power to the head-mounted unit on receiving the power supply instruction signal; and the main unit having a second power supply circuit including a battery for supplying electric power to the main unit on receiving the operation of a power supply switch and a second transmitter-receiver for transmitting the power supply instruction signal to the head-mounted unit by radio simultaneously with the power supplying to the main unit.