a current generating section including:

a current source that generates a current; and

a variable resistor of which the magnitude is variably set and which is configured by combining resistor elements at a predetermined ratio, the resistor elements having opposite characteristics to each other with respect to a temperature change,

wherein the magnitude of the generated current is adjusted by the variable resistor;

a start-up circuit section connected to the current generating section and fixing a bias operating point to a constant value such that the current generating section stably generates a current;

a charge and discharge circuit section including a variable capacitor, of which the magnitude is variably set, and a plurality of transistors, the charge and discharge circuit section charging and discharging the variable capacitor by using the current generated from the current generating section and the plurality of transistors;

an oscillation signal output section connected to the charge and discharge circuit section and including a plurality of inverters, the oscillation signal output section outputting an oscillation signal of which the frequency is determined by the resistance of the variable resistor and the capacitance of the variable capacitor; and

an inverter driving power supply section mirroring the current generated from the current generating section and then providing the mirrored current as a driving power supply of the inverters;

wherein the start-up circuit section includes first to third transistors, each of which is provided with first to third terminals and in which the magnitude and direction of a current flowing from the second terminal to the third terminal are varied on the basis of the magnitude of a voltage applied between the first and second terminals.