An endoscope system includes a light source for supplying three narrow wavelength bands including one wavelength band for exciting fluorescence, an excitation light cut filter for transmitting light having a wavelength greater than either 470 nm or 490 nm, and an image capturing unit for capturing the light transmitted by the excitation light cut filter and outputting three wavelength band signals corresponding to the three narrow wavelength bands of the light source. Also included are first, second and third frame memories for inputting and storing the three wavelength band signals, respectively, and first, second and third output ends for outputting first, second and third color signals, respectively, to a monitor for displaying an image. An image processor receives signals from the first, second and third frame memories respectively and selects among the first output end, the second output end and third output end for outputting the received signals to the monitor.