PURPOSE: To obtain a stable oscillated output whose duty is 50% without depending on the threshold voltage of a buffer by deciding the time in which the oscillated output is '0', and the time in which it is '1' by the time constant of a separately provided capacitor, in an oscillation circuit using a resistance and the capacitor.

CONSTITUTION: As for a charging circuit constituted of resistance 1 and 2, and capacitors 12 and 13, each capacitor 12 and 13 is connected so that the charge and the discharge can be alternately operated by two switch elements 8 and 10, and 9 and 11, the specific voltage of an integrated output is detected by a buffer 3, and output is frequency-divided by a frequency dividing circuit 5, and the capacitor charged by the output is switched, so that the time in which the oscillated output is '0', and the time in which the oscillated output is '1' can be decided by the charging time of the threshold voltage of the buffer 3. Thus, the duty ratio of the oscillated output depends only on the capacity value of the capacitor.