This apparatus for carrying out serial control comprises a plurality of node controllers each including a group of sensors (21S to 2nS), a group of actuators (21A to 2nA) or the like terminal components and a main controller for controlling the node controllers and the terminal components in an annular configuration or in a daisychain-shaped configuration. The main controller sends a frame signal which includes a first identification code (STI) indicative of the head position of sensor data and a second identification code (STO) indicative of the head position of actuator controlling data in one frame. Each node controller including a group of sensors feeds its own sensor data to a location just behind the first identification code of the received frame signal and sends to the subsequent stage the frame signal delayed by a length of the sensor data having the received frame signal fed thereto, subsequent to the signal having the sensor data fed thereto. Further, each node controller including a group of actuators extracts its own actuator control data from a location just behind a second identification code of the received frame signal and then sends the frame signal having the actuator control data extracted therefrom, subsequent to the frame signal which has been delayed by a length equivalent to the actuator control data having the received frame signal extracted therefrom.