To eliminate the centering work of a landing floor side sill for elevator in a construction field by fixing a landing floor side sill to each floor surface of plural units, performing the centering thereof at the same time, and piling these units in the construction field so as to structure a hoistway.

Sills 7, 3 are previously fixed to C-type steels 101a, 102a of units 101, 102 in a factory, performing the centering at the same time. These units 101, 102 are carried to a construction field, and the unit 102 is piled on the unit 101 so as to structure a hoistway. At this stage, each guide rail 104, 105 is previously fitted to the units 101, 102 in the factory. With this structure, the guide rails 104 and 105 are connected to each other by piling the unit 102 on the unit 101. Continuously, centering work of the guide rails 104, 105 is performed, namely, fitting position of the guide rails 104, 105 in the units 101, 102 is corrected. At this stage, even in the case where fitting position of the guide rails 104, 105 is corrected, positional displacement of the sills 7, 3 is not generated.