Abstract: A guide wire installation device for a catheter is formed of a catheter receiving section and a guide wire insertion section connected to the catheter receiving section. The catheter receiving section includes a first dent for receiving a distal end of the catheter, a first hole extending from the first dent, and a first slit extending laterally from the first dent and the first hole. The guide wire insertion section includes a second dent for inserting a guide wire, a second hole extending from the second dent and communicating substantially linearly with the first hole, and a second slit extending laterally from the second dent and the second hole. The guide wire can be easily inserted into the catheter through the installation device.