To easily perform main rope replacing work even in a limited work place, by shortening the suspending time of elevator service while shortening working time of main rope replacing work.

An allowance part 6b is provided on the lowermost floor, a new main rope 6 is fixed to a car 7, the new main rope is extended to the total length of a hoistway, the car and a counterweight 8 are fixed, an old main rope 6 is fixed in the position of the height of the car 7 in the hoistway and then cut just above it. A cage side part of the cut old main rope 6 is removed to a machine room 2, and the allowance part of the new main rope 6a is connected to the car 7 through a hoist 3. The old main rope 6 is cut and separated from the counterweight 8, and the lower end of the new main rope 6a is connected to the balance weight 8. The old main rope 6 fixed to the hoistway is moved to the car 7, and the old main rope 6 is recovered to the lowermost floor while lowering the car 7. Therefore, main rope changing work is facilitated, the work time is shortened, and work can be performed by using only the lower end of the hoisway even in a limited work place.