A power-on reset circuit, comprising: a bandgap reference circuit to which a power supply voltage is supplied, and which outputs a predetermined first voltage value (V A); a first start-up circuit causing the bandgap reference circuit to start a stable operation when a value of the power supply voltage becomes a first threshold value (V th1) or higher, wherein the first start-up circuit is connected to a power supply voltage terminal to which the power supply voltage is supplied; a voltage dividing circuit including: a switch (MP 3) and a first resistor (R 31) provided in series between the power supply voltage terminal to which the power supply voltage is supplied and an output terminal; and a second resistor (R 32) provided between the output terminal and a ground terminal, the voltage dividing circuit outputting a second voltage value (V B) from the output terminal; a second start-up circuit which causes the switch (MP 3) of the voltage dividing circuit to close when the value of the power supply voltage becomes a second threshold value (V th2) or higher which is greater than the first threshold value (V th1) wherein the second start-up circuit comprises: a transistor (MP 4) comprising a drain terminal connected, via a third resistor (R 43), to the ground terminal, and via an inverter (INV 4), to the switch (MP 3) of the voltage dividing circuit, the transistor (MP 4) further comprising a gate terminal connected, via a fourth resistor (R 41) to a power supply voltage terminal to which the power supply voltage is supplied, and via a fifth resistor (R 42), to the ground terminal; and a voltage comparison circuit receiving the first voltage value (V A) output from the bandgap reference circuit and the second voltage value (V B) output from the voltage dividing circuit, and outputting a reset level voltage value when the second voltage value (V B) is smaller than the first voltage value (V A) and outputting a power-supply voltage level voltage value if the second voltage value (V B) becomes the first voltage value (V A) or higher. a bandgap reference circuit to which a power supply voltage is supplied, and which outputs a predetermined first voltage value (V A); a first start-up circuit causing the bandgap reference circuit to start a stable operation when a value of the power supply voltage becomes a first threshold value (V th1) or higher, wherein the first start-up circuit is connected to a power supply voltage terminal to which the power supply voltage is supplied; a voltage dividing circuit including: a switch (MP 3) and a first resistor (R 31) provided in series between the power supply voltage terminal to which the power supply voltage is supplied and an output terminal; and a second resistor (R 32) provided between the output terminal and a ground terminal, a switch (MP 3) and a first resistor (R 31) provided in series between the power supply voltage terminal to which the power supply voltage is supplied and an output terminal; and a second resistor (R 32) provided between the output terminal and a ground terminal, the voltage dividing circuit outputting a second voltage value (V B) from the output terminal; a second start-up circuit which causes the switch (MP 3) of the voltage dividing circuit to close when the value of the power supply voltage becomes a second threshold value (V th2) or higher which is greater than the first threshold value (V th1) wherein the second start-up circuit comprises: a transistor (MP 4) comprising a drain terminal connected, via a third resistor (R 43), to the ground terminal, and via an inverter (INV 4), to the switch (MP 3) of the voltage dividing circuit, the transistor (MP 4) further comprising a gate terminal connected, via a fourth resistor (R 41) to a power supply voltage terminal to which the power supply voltage is supplied, and via a fifth resistor (R 42), to the ground terminal; and a voltage comparison circuit receiving the first voltage value (V A) output from the bandgap reference circuit and the second voltage value (V B) output from the voltage dividing circuit, and outputting a reset level voltage value when the second voltage value (V B) is smaller than the first voltage value (V A) and outputting a power-supply voltage level voltage value if the second voltage value (V B) becomes the first voltage value (V A) or higher. a transistor (MP 4) comprising a drain terminal connected, via a third resistor (R 43), to the ground terminal, and via an inverter (INV 4), to the switch (MP 3) of the voltage dividing circuit, the transistor (MP 4) further comprising a gate terminal connected, via a fourth resistor (R 41) to a power supply voltage terminal to which the power supply voltage is supplied, and via a fifth resistor (R 42), to the ground terminal; and a voltage comparison circuit receiving the first voltage value (V A) output from the bandgap reference circuit and the second voltage value (V B) output from the voltage dividing circuit, and outputting a reset level voltage value when the second voltage value (V B) is smaller than the first voltage value (V A) and outputting a power-supply voltage level voltage value if the second voltage value (V B) becomes the first voltage value (V A) or higher.