An endoscope apparatus comprising: a light source section that includes a semiconductor light source that is configured to emit excitation light and a fluorescent substance that is configured to emit fluorescence by being excited by the excitation light, and emit synthesized light of the excitation light and the fluorescence as illumination light; an image pickup section that is configured to pick up an image of an observation part illuminated by the illumination light; a video signal processing section that is configured to convert an image pickup signal outputted by the image pickup section to a video signal; and a light adjusting circuit that is configured to generate setting value information having a pulse width of a PWM signal for causing the semiconductor light source to emit light, based on an inputted timing signal, a setting signal of a luminance level, and a luminance signal outputted from the video signal processing section, and control brightness of the illumination light emitted from the light source section by adjusting driving time of the semiconductor light source in each image pickup period of the image pickup section based on the setting value information; wherein the video signal processing section includes: a color correction parameter deriving section that is configured to derive a first correction parameter for correcting the video signal of a first color, and a second correction parameter, which is different from the first correction parameter, for correcting the video signal of a second color, based on the setting value information and on a pair of thresholds defined in advance as upper and lower limit values of a driving time of the semiconductor light source in which appropriate color balance is maintained based on a relation between the driving time of the semiconductor light source and color balance of illumination light; and a color correcting section that is configured to correct the gain of the video signal of the first color with the first correction parameter, and correct the gain of the video signal of the second color with the second correction parameter. a light source section that includes a semiconductor light source that is configured to emit excitation light and a fluorescent substance that is configured to emit fluorescence by being excited by the excitation light, and emit synthesized light of the excitation light and the fluorescence as illumination light; an image pickup section that is configured to pick up an image of an observation part illuminated by the illumination light; a video signal processing section that is configured to convert an image pickup signal outputted by the image pickup section to a video signal; and a light adjusting circuit that is configured to generate setting value information having a pulse width of a PWM signal for causing the semiconductor light source to emit light, based on an inputted timing signal, a setting signal of a luminance level, and a luminance signal outputted from the video signal processing section, and control brightness of the illumination light emitted from the light source section by adjusting driving time of the semiconductor light source in each image pickup period of the image pickup section based on the setting value information; wherein the video signal processing section includes: a color correction parameter deriving section that is configured to derive a first correction parameter for correcting the video signal of a first color, and a second correction parameter, which is different from the first correction parameter, for correcting the video signal of a second color, based on the setting value information and on a pair of thresholds defined in advance as upper and lower limit values of a driving time of the semiconductor light source in which appropriate color balance is maintained based on a relation between the driving time of the semiconductor light source and color balance of illumination light; and a color correcting section that is configured to correct the gain of the video signal of the first color with the first correction parameter, and correct the gain of the video signal of the second color with the second correction parameter. a color correction parameter deriving section that is configured to derive a first correction parameter for correcting the video signal of a first color, and a second correction parameter, which is different from the first correction parameter, for correcting the video signal of a second color, based on the setting value information and on a pair of thresholds defined in advance as upper and lower limit values of a driving time of the semiconductor light source in which appropriate color balance is maintained based on a relation between the driving time of the semiconductor light source and color balance of illumination light; and a color correcting section that is configured to correct the gain of the video signal of the first color with the first correction parameter, and correct the gain of the video signal of the second color with the second correction parameter.