An endoscope system includes: an LVDS driver that outputs a differential signal; a differential transmission line that transmits the differential signal outputted from the LVDS driver; a pulse transformer including, in order to input the differential signal transmitted by the differential transmission line, two input terminals connected to an end of the differential transmission line; a resistor functioning as a bypass impedance element connected on an input side of the pulse transformer, to which the differential signal is inputted, in parallel to the pulse transformer and having, at a predetermined noise frequency of noise mixed in the differential transmission line, impedance smaller than circuit impedance of a circuit to which the pulse transformer, which is connected in parallel to the bypass impedance element, is connected; and a dielectric disposed between the two input terminals of the pulse transformer and between lines of the differential transmission line.