An illumination device, comprising: an illumination light source having a plurality of light emitting diodes (3R, 3G, 3B) with different light colors; driving means (22R, 22G, 22B) adapted to make a plurality of light emitting diodes (3R, 3G, 3B) emit light individually and with an arbitrary light amount; operation input receiving means adapted to receive an operation input by a human; and determination means including a control signal input part and a drive signal converting part adapted to determine the light amount of each light emitting diode (3R, 3G, 3B) of the illumination light source so that a color temperature and a light amount of illumination light irradiated from the illumination light source are a color temperature and a light amount corresponding to an operation input received at the operation input receiving means, wherein: the driving means (22R, 22G, 22B) makes each light emitting diode (3R, 3G, 3B) emit light with the light amount determined by the determination means (20, 23); and the determination means (20, 23) determines, by converting, using the drive signal converting part, a control signal generated based on the operation input and inputted to the control signal input part into drive signals to be fed to the driving means (22R, 22G, 22B), a light amount of each light emitting diode (3R, 3G, 3B) of the illumination light source so that the color temperature and the light amount of the illumination light increase and decrease in conjunction with each other corresponding to a change in the operation input within a range lower than a color temperature at the time of rated lighting of the illumination light source, and chromaticity of the illumination light varies along a blackbody locus, as well as that based on the conjunction between the color temperature and the amount of the illumination light an increase and a decrease in a color temperature corresponding to a change in the operation input at a first time is larger than an increase and a decrease in a color temperature corresponding to the change in the operation input at a second time, wherein the light amount at the first time is smaller than the light amount at the second time. an illumination light source having a plurality of light emitting diodes (3R, 3G, 3B) with different light colors; driving means (22R, 22G, 22B) adapted to make a plurality of light emitting diodes (3R, 3G, 3B) emit light individually and with an arbitrary light amount; operation input receiving means adapted to receive an operation input by a human; and determination means including a control signal input part and a drive signal converting part adapted to determine the light amount of each light emitting diode (3R, 3G, 3B) of the illumination light source so that a color temperature and a light amount of illumination light irradiated from the illumination light source are a color temperature and a light amount corresponding to an operation input received at the operation input receiving means, wherein: the driving means (22R, 22G, 22B) makes each light emitting diode (3R, 3G, 3B) emit light with the light amount determined by the determination means (20, 23); and the determination means (20, 23) determines, by converting, using the drive signal converting part, a control signal generated based on the operation input and inputted to the control signal input part into drive signals to be fed to the driving means (22R, 22G, 22B), a light amount of each light emitting diode (3R, 3G, 3B) of the illumination light source so that the color temperature and the light amount of the illumination light increase and decrease in conjunction with each other corresponding to a change in the operation input within a range lower than a color temperature at the time of rated lighting of the illumination light source, and chromaticity of the illumination light varies along a blackbody locus, as well as that based on the conjunction between the color temperature and the amount of the illumination light an increase and a decrease in a color temperature corresponding to a change in the operation input at a first time is larger than an increase and a decrease in a color temperature corresponding to the change in the operation input at a second time, wherein the light amount at the first time is smaller than the light amount at the second time. the driving means (22R, 22G, 22B) makes each light emitting diode (3R, 3G, 3B) emit light with the light amount determined by the determination means (20, 23); and the determination means (20, 23) determines, by converting, using the drive signal converting part, a control signal generated based on the operation input and inputted to the control signal input part into drive signals to be fed to the driving means (22R, 22G, 22B), a light amount of each light emitting diode (3R, 3G, 3B) of the illumination light source so that the color temperature and the light amount of the illumination light increase and decrease in conjunction with each other corresponding to a change in the operation input within a range lower than a color temperature at the time of rated lighting of the illumination light source, and chromaticity of the illumination light varies along a blackbody locus, as well as that based on the conjunction between the color temperature and the amount of the illumination light an increase and a decrease in a color temperature corresponding to a change in the operation input at a first time is larger than an increase and a decrease in a color temperature corresponding to the change in the operation input at a second time, wherein the light amount at the first time is smaller than the light amount at the second time.