PROBLEM TO BE SOLVED: To provide an endoscope system capable of reducing the diameter of a power supply signal line to an image pickup device while securing operation guarantee of the image pickup device, and consequently achieving the diameter reduction of an endoscope itself.SOLUTION: An endoscope system includes: a tip desired voltage generation unit 53 for supplying power to a CMOS sensor 11 through a power source signal line 41； a current detection unit 55 for detecting a current value of the power source signal line 41； a gain circuit unit 57 for obtaining a voltage command value corresponding to a voltage drop in the power source signal line 41 based on a resistance value R1 related to the power source signal line 41 and the current value detected by the current detection unit 55； and a voltage generation unit 52 for controlling the tip desired voltage generation unit 53 so as to apply a predetermined voltage to the CMOS sensor 11 based on the voltage command value obtained in the gain circuit 57.SELECTED DRAWING: Figure 1【課題】撮像素子の動作保障を確保しながら撮像素子への電源供給信号線の細径化を可能とし、ひいては内視鏡自体の細径化を実現する内視鏡システムを提供する。【解決手段】ＣＭＯＳセンサ１１に電源信号線４１を介して電力を提供する先端所望電圧生成部５３と、電源信号線４１の電流値を検出する電流検知部５５と、電源信号線４１に係る抵抗値Ｒ１と電流検知部５５において検出した電流値とに基づいて電源信号線４１における電圧降下分に対応した電圧指令値を求めるゲイン回路５７と、ゲイン回路５７において求めた電圧指令値に基づいて、ＣＭＯＳセンサ１１に所定電圧を印加するよう先端所望電圧生成部５３を制御する電圧生成部５２と、を具備する。【選択図】図１
