PURPOSE: To provide a triangular wave generating circuit with which an accurate triangular wave is generated.

CONSTITUTION: A reference voltage VH set at the node of resistors R33 and R34 is guided through transistors Q45 and Q46 to a point D, a reference voltage VL set at the node of resistors R34 and R35 is guided through transistors Q47 and Q48 to the point D, and either the voltage VH or the voltage VL is supplied to the base of a transistor Q34 consisting of one part of a triangular wave comparing part 1 as a reference voltage by voltage switching processing at a reference voltage switching part 3. On the other hand, a voltage based on electric changes in a capacitor Cf by charging/discharging a capacitor charging part 4 is impressed to the base of a transistor Q35 consisting of one part of the triangular wave comparing part 1 as a comparative voltage and according to the levels of this comparative voltage and the reference voltage, potentials at points B and C are set. Then, the potential at a point F (the capacitor Cf) is outputted as a triangular wave signal.