An endoscope apparatus 8 includes: a region dividing portion 51 that divides an endoscope image into a center region and a peripheral region a brightness mean value calculation portion 58 that has a peripheral brightness mean value calculation portion 55 that calculates a peripheral brightness mean value, and a center brightness mean value calculation portion 52 that calculates a center brightness mean value a first weighting factor calculation portion 53 that calculates a first weighting factor ± (where 0 < ± < 1) based on a ratio between a center brightness mean value and a peripheral brightness mean value a first photometric value calculation portion 54 that calculates a first photometric value based on a sum total of a value obtained by multiplying a center brightness mean value by the first weighting factor ± and a value obtained by multiplying the peripheral brightness mean value by (1-±) and a brightness adjustment control portion 70 that generates a brightness adjustment control signal for adjusting the brightness of the endoscope image based on the first photometric value.
