An endoscope system 1 includes: an LVDS driver 41 that outputs a differential signal a differential transmission line 50 that transmits the differential signal outputted from the LVDS driver 41 a pulse transformer 42 that is connected to an end of the differential transmission line and to which the differential signal transmitted by the differential transmission line 50 is inputted a resistor 54 functioning as a bypass impedance element connected on an input side of the pulse transformer 42, to which the differential signal is inputted, in parallel to the pulse transformer 42. The impedance of the resistor 54 is smaller than circuit impedance on the pulse transformer 42 side at a noise frequency.