A visible light communication device, comprising: a light source comprising a light-emitting device (LDi); an impedance circuit which has an impedance device and is connected in series with the light source; a switch circuit which is connected in parallel with the impedance circuit and is configured so that a load current flows through the light source without flowing through the impedance circuit when the switch circuit is turned on while a load current flows through the light source via the impedance circuit when the switch circuit is turned off, thereby connecting or disconnecting the impedance circuit to/from the light source; and a first controller which is configured to perform ON and OFF control of the switch circuit and thereby to modulate an intensity of an illumination light emitted from the light source to superpose a binary communication signal on the illumination light; characterized by an impedance-varying circuit (Q2, Q3, Q20-Q22) which is connected with the impedance circuit and configured to change an impedance of the impedance circuit; and a second controller which is configured to control the impedance-varying circuit (Q2, Q3, Q20-Q22) to change the impedance of the impedance circuit, wherein the first and second controllers (3, 4) share a microcontroller as a common hardware, and wherein the impedance circuit: a) is formed of a series circuit of a resistor and a body diode of a MOSFET as the impedance-varying circuit; b) is formed of a series circuit of a diode and a body diode of a MOSFET operating as the impedance-varying circuit; c) comprises body diodes (BD1-BD3) of a series circuit of two or more switching devices (Q20-Q22) operating as the impedance-varying circuit, wherein the series circuit of two or more switching devices (Q20-Q22) is connected in parallel with the switch circuit; d) is formed of a series circuit of a first resistor, a second resistor and a third resistor, the impedance-varying circuit comprising: a switching device connected in parallel with a series circuit of the second and third resistors (RX2 and RX3); and a switching device connected in parallel with the third resistor; or e) is connected in parallel with the switch circuit and formed of a resistor, a bipolar transistor as a variable resistor, and an emitter resistor (Re). a light source comprising a light-emitting device (LDi); an impedance circuit which has an impedance device and is connected in series with the light source; a switch circuit which is connected in parallel with the impedance circuit and is configured so that a load current flows through the light source without flowing through the impedance circuit when the switch circuit is turned on while a load current flows through the light source via the impedance circuit when the switch circuit is turned off, thereby connecting or disconnecting the impedance circuit to/from the light source; and a first controller which is configured to perform ON and OFF control of the switch circuit and thereby to modulate an intensity of an illumination light emitted from the light source to superpose a binary communication signal on the illumination light; characterized by an impedance-varying circuit (Q2, Q3, Q20-Q22) which is connected with the impedance circuit and configured to change an impedance of the impedance circuit; and a second controller which is configured to control the impedance-varying circuit (Q2, Q3, Q20-Q22) to change the impedance of the impedance circuit, wherein the first and second controllers (3, 4) share a microcontroller as a common hardware, and wherein the impedance circuit: a) is formed of a series circuit of a resistor and a body diode of a MOSFET as the impedance-varying circuit; b) is formed of a series circuit of a diode and a body diode of a MOSFET operating as the impedance-varying circuit; c) comprises body diodes (BD1-BD3) of a series circuit of two or more switching devices (Q20-Q22) operating as the impedance-varying circuit, wherein the series circuit of two or more switching devices (Q20-Q22) is connected in parallel with the switch circuit; d) is formed of a series circuit of a first resistor, a second resistor and a third resistor, the impedance-varying circuit comprising: a switching device connected in parallel with a series circuit of the second and third resistors (RX2 and RX3); and a switching device connected in parallel with the third resistor; or e) is connected in parallel with the switch circuit and formed of a resistor, a bipolar transistor as a variable resistor, and an emitter resistor (Re). a) is formed of a series circuit of a resistor and a body diode of a MOSFET as the impedance-varying circuit; b) is formed of a series circuit of a diode and a body diode of a MOSFET operating as the impedance-varying circuit; c) comprises body diodes (BD1-BD3) of a series circuit of two or more switching devices (Q20-Q22) operating as the impedance-varying circuit, wherein the series circuit of two or more switching devices (Q20-Q22) is connected in parallel with the switch circuit; d) is formed of a series circuit of a first resistor, a second resistor and a third resistor, the impedance-varying circuit comprising: a switching device connected in parallel with a series circuit of the second and third resistors (RX2 and RX3); and a switching device connected in parallel with the third resistor; or e) is connected in parallel with the switch circuit and formed of a resistor, a bipolar transistor as a variable resistor, and an emitter resistor (Re).