Abstract: A high-functional computer sewing machine can be obtained at a low cost. The inventive computer sewing machine comprises a data signal input/output part and a control part. The data signal input/output part transmits/receives a data signal to/from an externally set data input/output unit by data communication through any of a transmission line, radio and light. The control part controls the operation of a sewing machine body on the basis of the data signal from the data input/output unit received by the data signal input/output part. Thus, when using a commercially available game machine or the like as the data input/output unit, no data input/output unit dedicated to the sewing machine need be separately purchased while the sewing machine body need not be provided with a high-priced liquid crystal touch panel for inputting data.