PURPOSE: To simplify the tieing work of the single wire by a method wherein the single wire is turned by 180° to make a semi-circular end part and a duplicated part while one set of tool is utilized in a specified manner.

CONSTITUTION: The duplicated part 2b of the single wire 2, in which the semi- circular end part 2a is made by turning it by 180°, is turned by 180° about a fixed jig 4, 5, subsequently, the end 6a of the tool 6 is inserted into the end part 2a and is turned about the part 2b to twist the part 2b, thereafter, the end 6a is withdrawn from the end part 2a and the end part 2a is inserted into a circular part 7 constituted with the fixed jig 4, 5, the part 2b and the twisted part 2c, whereby the wire 2 is tied about the fixed jug 4, 5. This method is utilized in case the solar heat hot-water heater is fixed to a roof or the like.