To manufacture a mat (Japanese tatami) with high accuracy in shape by mounting a color sensor for detecting a reference line of a cutting edge of a mat facing, and properly sewing a mat border to a mat base on a position inside of a cutting edge of the mat facing by a specific length on the basis of the information detected by this sensor.

When a color sensor 27 is moved on a cutting line (s) on a mat facing (w1) by the movement of a cutting and sewing head, and detects a color phase (mixture of color phase of mat base (w) and color phase (w1) of mat facing) different from the color phase of an upper surface of the mat base (w), an electronic switch circuit device compares the information detected on this occasion with the information stored in advance, judges the immediate stop of the cutting and sewing head, and transmits the switch output corresponding to the judgement. Whereby the motor stops its motion. The motor is stopped until the color sensor 27 detects the color phase of the upper surface of the mat base (w) or the color phase of the upper surface of the mat facing (w1), and the lateral movement of the cutting and sewing head is stopped.