Disclosed is a method of controlling the supply of a clock signal to a logic circuit, especially, a logic circuit composed of C-MOS gates for further reducing the power consumption. According to the control method, a clock signal supply inhibit instruction is stored, so that, when this instruction is read out, the supply of the clock signal to the logic circuit is inhibited, or its level is fixed at a specific signal level. In response to the application of an interrupt signal, the clock signal having been inhibited to be supplied to the logic circuit starts to be supplied to the logic circuit again. The circuit region or regions for which the supply of the clock signal is to be inhibited can be freely selected for the purpose of control. Thus, the method is especially effective when it is desired to closely control the saving of power consumed by the logic circuit.