Abstract: A sewing maching having associated modules which can be inserted at will and which are interchangeable in a guide of the housing of the machine. The front side of the plate-shaped modules is visible in the inserted condition of the module and is provided with stitch symbols to which are assigned numbers. On the inside of the modules are arranged memories, preferably in connection with a microprocessor, which are in connection with the microprocessor of the sewing machine when the modules are inserted. By means of keys and a display, the number corresponding to the desired stitch sort can be selected and the control data from the memories of the module will be recalled in the microprocessor of the sewing machine and then used for controlling operation of the sewing machine.