PURPOSE: To quickly perform the character transmission/ reception processing by providing a start-stop system terminal equipment with a processing determing means which retrieves the classification of the processing for a character based on the character code which identifies the transmitted/received character.

CONSTITUTION: A reception character processing part 32 and a transmission character processing part 37 are provided with processing determination tables 321 and 371 respectively as processing determining means 200. When a start-stop system terminal equipment 1 transmits a character string 6 consisting of general characters A, B, C, D, E, and F and a control character C/R to a start-stop system terminal equipment 2, character reception report is transmitted to the reception character processing part 32 when a communication control part 31 of a packet composer/decomposer 3 receives the first general character A from the start-stop system terminal equipment 1. The reception character processing part 32 retrieves the processing determination table 321 by a character code Ci of the reception character to obtain a corresponding processing identification code Pj and determines a corresponding processing based on the obtained processing identification code Pj each time when the character is received.