PURPOSE: To decrease the temperature dependancy of an oscillated frequency by using a temperature compensation diode so as to connect a gate and a drain of a couple of FETs forming a current source.

CONSTITUTION: The oscillating frequency f0 of the circuit is expressed as fo=I/4 CB, where I is a drain current flowing through FETs Q3, Q4, C is the capaci tance of a capacitor C1 and B is a barrier potential of diodes D1, D2. When temperature raises, the potential B of the diodes D1, D2 is lowered and since the barrier potential B of the diode D5 is lowered similarly in this case, the gate potential of the FETs Q3, Q4 is lowered and the drain current I flowing to the FETs Q3, Q4 is lowered. That is, the increase in the oscillating frequency fo due to the reduction in the barrier potential B is cancelled by the decrease in the drain current I, then the temperature dependancy of the oscillating fre quency f0 is decreased.