To provide a portable threading device so designed as to be easily carried out replacement of the die head.

An annular groove 8 with which the tip of a set screw 9 on the carriage 3 side engages and a linear groove which extends from the annular groove 8 to a die head pin 7 are provided on the periphery of the die head pin 7 which is to attach a die head 6 to the carriage 3 in such a way as it can rise and flatten. It is thereby possible to pull out the die head pin 7 without removing the set screw 9 only by rotating the die head 6 to a predetermined angle to match the linear groove of the die head pin 7 with the tip of the set screw 9.