Transmission of electric and optical signal, realization of high-speed and
high capacity of transmission of information signals. A base substrate
section having an interconnect layer formed on an insulating substrate by
a printed circuit process; a micro interconnect circuit section having a
micro electrical interconnect layer which is finer than the interconnect
layer of the base substrate section, formed on an insulating resin layer
by a semiconductor process; and an optical interconnect circuit section
adapted to transfer and/or receive an optical signal and provided with an
optical wave-guide having an input section and an output section of a
optical signal at opposite ends thereof; and at least a pair of optical
elements composed of a light emitting device with a light emitting
section thereof facing the input section and a photo detecting device
with a photo detecting section thereof facing the output section are
provided and the micro interconnect circuit section and the optical
interconnect circuit section are mounted on the base substrate section.