An endoscope system includes: an illumination unit configured to irradiate a visual field area with illumination light that produces return light from a specific substance a sensor unit having a two-dimensional surface on which a plurality of pixels is arranged for receiving the return light from the visual field area and photoelectrically converting the return light to generate electrical signals, the sensor unit being configured to sequentially read out the electrical signals generated by the plurality of pixels, as image information a reset pulse generation unit configured to generate reset pulses for releasing electric charges accumulated in the plurality of pixels and a reset pulse controller configured to adjust timing of generating the reset pulses such that at least a part of a plurality of frames of an image is included in a period between generation of two consecutive reset pulses.
