An endoscope apparatus (1) according to the present invention includes: a light source unit (3) that emits white light or narrow-band light as illumination light an image sensor (202) having a plurality of pixels a color filter (202a) including a filter unit having a plurality of filters in which the number of filters for passing green wavelength band light and the number of filters for passing blue wavelength band light satisfy predetermined conditions a first gain adjustment unit (411) that adjusts a gain of an electric signal generated by the image sensor (202) a demosaicing processing unit (412) that generates an image signal of a color component passing through a filter based on the electric signal whose gain has been adjusted by the first gain adjustment unit (411) a color conversion processing unit (413) that performs color conversion processing on an image signal when the light source unit (3) emits the white illumination light and a second gain adjustment unit (414) that adjusts a gain of each image signal subjected to the color conversion processing.
