An LED illumination device adapted to be connected to a power supply device , wherein the power supply device includes a constant voltage circuit configured to generate a constant voltage and a constant current circuit configured to variably set a supply current, and the LED illumination device includes a first terminal adapted to be connected to the constant voltage circuit and a second terminal adapted to be connected to the constant current circuit , the LED illumination device comprising: an LED circuit ; a bypass circuit ; and a distribution circuit configured to distribute the supply current supplied from the power supply device at a predetermined ratio regardless of a current value and configured to supply one part thereof to the LED circuit and the other part thereof to the bypass circuit , wherein the distribution circuit includes: a first resistance element (R1) arranged in series with the LED circuit ; a second resistance element (R2) arranged in series with the bypass circuit ; and a voltage maintaining circuit configured to maintain voltages applied to the first resistance element (R1) and the second resistance element (R2) so that the voltages are substantially equal, and wherein the predetermined ratio is determined based on a resistance value of the first resistance element (R1) and a resistance value of the second resistance element (R2), wherein the voltage maintaining circuit includes: a differential amplifier circuit having a pair of input terminals (a, b); a feedback circuit configured to perform a feedback operation so as to keep potentials of the respective input terminals (a, b) equal; and a pair of transistors (Q1, Q2) having emitters connected to the respective input terminals (a, b), so that base potentials are kept equal, wherein the first resistance element (R1) is arranged between the base of the first transistor (Q1) and the first terminal , and the LED circuit is arranged between the base of the first transistor (Q1) and the second terminal , and wherein the second resistance element (R2) is arranged between the base of the second transistor (Q2) and the first terminal , and the bypass circuit is arranged between the base of the second transistor (Q2) and the second terminal . an LED circuit ; a bypass circuit ; and a distribution circuit configured to distribute the supply current supplied from the power supply device at a predetermined ratio regardless of a current value and configured to supply one part thereof to the LED circuit and the other part thereof to the bypass circuit , a first resistance element (R1) arranged in series with the LED circuit ; a second resistance element (R2) arranged in series with the bypass circuit ; and a voltage maintaining circuit configured to maintain voltages applied to the first resistance element (R1) and the second resistance element (R2) so that the voltages are substantially equal, and a differential amplifier circuit having a pair of input terminals (a, b); a feedback circuit configured to perform a feedback operation so as to keep potentials of the respective input terminals (a, b) equal; and a pair of transistors (Q1, Q2) having emitters connected to the respective input terminals (a, b), so that base potentials are kept equal, <EOS>