An endoscope system, comprising: an endoscope that includes an illuminating fiber that guides an illuminating light that is emitted from a light source, an optical system that irradiates the illuminating light that is guided by the illuminating fiber onto an object, and a drive portion that rocks the illuminating fiber so that an irradiation position of the illuminating light that is irradiated onto the object through the optical system is an irradiation position along a predetermined scanning pattern; a coordinate information acquisition portion that acquires coordinate information that can identify an irradiation position of the illuminating light that is irradiated along the predetermined scanning pattern; a storage portion (11, 16) in which optical characteristics information is previously stored that, in a case where light of a predetermined wavelength band is set as a standard of chromatic aberration of magnification that is caused by the optical system, shows a correlation between an image height and an aberration amount of light of another wavelength band; a correction information acquisition portion that: upon detecting that the light of the predetermined wavelength band is irradiated onto a position corresponding to a predetermined image height based on the coordinate information, detects an aberration amount of the light of the other wavelength band at the predetermined image height based on the optical characteristics information that is stored in the storage portion (11, 16); calculates a proportion that the detected aberration amount occupies with respect to a maximum image height that is determined in accordance with a maximum amplitude of the illuminating fiber that is rocked by the drive portion; and acquires the value of the calculated proportion as image correction information that is used for correcting chromatic aberration of magnification of an image that is generated in accordance with return light of the light of the other wavelength band; and an image processing portion that performs image correction processing based on the proportion acquired as the image correction information. an endoscope that includes an illuminating fiber that guides an illuminating light that is emitted from a light source, an optical system that irradiates the illuminating light that is guided by the illuminating fiber onto an object, and a drive portion that rocks the illuminating fiber so that an irradiation position of the illuminating light that is irradiated onto the object through the optical system is an irradiation position along a predetermined scanning pattern; a coordinate information acquisition portion that acquires coordinate information that can identify an irradiation position of the illuminating light that is irradiated along the predetermined scanning pattern; a storage portion (11, 16) in which optical characteristics information is previously stored that, in a case where light of a predetermined wavelength band is set as a standard of chromatic aberration of magnification that is caused by the optical system, shows a correlation between an image height and an aberration amount of light of another wavelength band; a correction information acquisition portion that: upon detecting that the light of the predetermined wavelength band is irradiated onto a position corresponding to a predetermined image height based on the coordinate information, detects an aberration amount of the light of the other wavelength band at the predetermined image height based on the optical characteristics information that is stored in the storage portion (11, 16); calculates a proportion that the detected aberration amount occupies with respect to a maximum image height that is determined in accordance with a maximum amplitude of the illuminating fiber that is rocked by the drive portion; and acquires the value of the calculated proportion as image correction information that is used for correcting chromatic aberration of magnification of an image that is generated in accordance with return light of the light of the other wavelength band; and an image processing portion that performs image correction processing based on the proportion acquired as the image correction information. upon detecting that the light of the predetermined wavelength band is irradiated onto a position corresponding to a predetermined image height based on the coordinate information, detects an aberration amount of the light of the other wavelength band at the predetermined image height based on the optical characteristics information that is stored in the storage portion (11, 16); calculates a proportion that the detected aberration amount occupies with respect to a maximum image height that is determined in accordance with a maximum amplitude of the illuminating fiber that is rocked by the drive portion; and acquires the value of the calculated proportion as image correction information that is used for correcting chromatic aberration of magnification of an image that is generated in accordance with return light of the light of the other wavelength band; and an image processing portion that performs image correction processing based on the proportion acquired as the image correction information.