PURPOSE:To make easy the circuit integration, by the constitution that charge/ discharge is made only one electrode side of a capacitive element. CONSTITUTION:As the initial state, when the Q output of FF19 is at low level, the switch 12 is on and the switch 13 is off. In this case, the constant current source 11 connected to the power supply terminal 21 charges up one electrode of the capacitive element 18 via the switch 12. When the potential at the connecting point 16 is greater than the threshold voltage Vt of the inverter 22a with this charging, the output of the inverting circuit 22b is at high level, FF19 is set, and the Q output is at high level. Thus, the switch 12 is off and 13 is on, and the charge stored in the capacitive element 18 is discharged via the switch 13. During this discharge, the output of the delay circuit 23 is at high level, FF19 is reset, and the Q output is at low level, to be returned into the initial state. The operation like this is repeated and the oscillation output is obtained.