Sequential control circuit for sequentially controlling the operation of mechanical equipment, for example, an electrophotographic copying apparatus including various devices having respective smaller devices is characterized in that a first train of clock pulses having a fixed predetermined frequency is converted into a third train of clock pulses whose respective pulses are in synchronism with respective pulses of a second train of clock pulses sequentially generated in accordance with respective driven rates of the sequentially driven devices, so that a respective digital timer circuit which is preset with operational time data of its respective device is capable of successively performing the decrement of the predetermined time in response to the respective pulses of the respective third train of clock pulses.