An endoscope apparatus 1 includes a flash memory 19 that stores a reference value of a color balance adjustment value of an endoscopic image of an endoscope 2 that picks up an object through a polarizer 18a, 18b. The endoscope calculates, from the reference value and the color balance adjustment value of the endoscope 2 after elapse of a predetermined time period, an amount of change in the color balance adjustment value judges whether or not the calculated amount of change is equal to or larger than a predetermined threshold and, when the amount of change is equal to or larger than the predetermined threshold, outputs a predetermined output.
