A simple monostable multivibrator circuit using a complementary pair of transistors is described. In comparison with the conventional configuration, this circuit has such features that it would need no standing power and a smaller number of components. The commonemitter current amplification factor, hfe, of the transistors may be made as the overriding factor for the pulse width control and thus, enables a small combination of C-R to be used for long time-delay. However, the sensitivity of the pulse width on the transistor current amplification factor, hfe, may be reduced, if desired, in the improved circuit.