Light source lighting circuit comprising: a) a driving voltage generating circuit configured to supply a driving voltage to a light source; and b) a control circuit configured to control the driving voltage generating circuit, the control circuit including: b1) a plurality of processing circuits (54, 58) configured to control (S1-S4) the driving voltage generating circuit using corresponding control voltages (V E1, V E2) respectively, b2) an environment information converting circuit configured to convert information indicative of an environment of an operation into a state current (I S) based on a predetermined converting rule, and characterized by b3) a control voltage generating circuit configured to generate the control voltages (V E1, V E2) for the processing circuits and configured to regulate each of the control voltages (V E1, V E2) by using the state current (I S), b4) wherein for at least one of the control voltages (V E1, V E2), the control voltage generating circuit is configured to divide a reference voltage (V CC) by a resistive element (R1, R2; R3, R4) and set, as a control voltage (V E1, V E2), a voltage (V N1, V N2) on a voltage dividing point (N1; N2) which is obtained by causing the state current (I S) to flow to the voltage dividing point (N1; N2). a) a driving voltage generating circuit configured to supply a driving voltage to a light source; and b) a control circuit configured to control the driving voltage generating circuit, the control circuit including: b1) a plurality of processing circuits (54, 58) configured to control (S1-S4) the driving voltage generating circuit using corresponding control voltages (V E1, V E2) respectively, b2) an environment information converting circuit configured to convert information indicative of an environment of an operation into a state current (I S) based on a predetermined converting rule, and characterized by b3) a control voltage generating circuit configured to generate the control voltages (V E1, V E2) for the processing circuits and configured to regulate each of the control voltages (V E1, V E2) by using the state current (I S), b4) wherein for at least one of the control voltages (V E1, V E2), the control voltage generating circuit is configured to divide a reference voltage (V CC) by a resistive element (R1, R2; R3, R4) and set, as a control voltage (V E1, V E2), a voltage (V N1, V N2) on a voltage dividing point (N1; N2) which is obtained by causing the state current (I S) to flow to the voltage dividing point (N1; N2). b1) a plurality of processing circuits (54, 58) configured to control (S1-S4) the driving voltage generating circuit using corresponding control voltages (V E1, V E2) respectively, b2) an environment information converting circuit configured to convert information indicative of an environment of an operation into a state current (I S) based on a predetermined converting rule, and characterized by b3) a control voltage generating circuit configured to generate the control voltages (V E1, V E2) for the processing circuits and configured to regulate each of the control voltages (V E1, V E2) by using the state current (I S), b4) wherein for at least one of the control voltages (V E1, V E2), the control voltage generating circuit is configured to divide a reference voltage (V CC) by a resistive element (R1, R2; R3, R4) and set, as a control voltage (V E1, V E2), a voltage (V N1, V N2) on a voltage dividing point (N1; N2) which is obtained by causing the state current (I S) to flow to the voltage dividing point (N1; N2).