An endoscope system includes: an endoscope scope insertion portion having an insertion portion that is configured to be inserted inside a living organism and is provided with an observation device which is capable of making observations on the distal end side thereof； an extracorporeal device which is disposed outside the living organism； a first scope-side signal connecting portion that is provided on the endoscope scope insertion portion and has a first electrode which is electrically connected to the endoscope scope insertion portion； and a cylindrical first extracorporeal-side signal connecting portion that is provided on the extracorporeal device and has a second electrode which is electrically connected to the extracorporeal device, the first extracorporeal-side signal connecting portion configured to engage with the first scope-side signal connecting portion. In this endoscope system, when the first scope-side signal connecting portion is engaged with the first extracorporeal-side signal connecting portion, at least a portion of the first scope-side signal connecting portion is located within an inside-cylinder space of the first extracorporeal-side signal connecting portion, and the first electrode and the second electrode are electrostatically coupled together.
