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; a reading unit configured to read out the electrical signals per a specified frame cycle; a reset pulse generation unit configured to generate reset pulses for releasing electric charges accumulated in the plurality of pixels; a reset pulse controller configured to adjust timing of generating the reset pulses such that a plurality of frame cycles is included in a period between generation of two consecutive reset pulses; and an illumination controller configured to cause the illumination unit to emit the illumination light in each of the plurality of frame cycles.