PURPOSE: To drain a waterdrop of an inner wall without narrowing the effective area of a lift passage by arranging plural horizontal gutter of down slope in the height direction on the inner wall of the lift passage and connecting the mutual horizontal gutters by a tubular vertical gutter.

CONSTITUTION: The horizontal gutter 21 opening to the upper part in U or Z like sectional face is plurally provided in the height direction of a lift passage 1 by inclining slightly for the horizontal face along the inner wall 11 of the lift passage. The mutual space of the horizontal gutter 21 is linked by a tubular vertical gutter 22, the waterdrop generated on the lift passage wall 11 is received by the horizontal gutter 21, dropped to the horizontal gutter 21 underneath by collecting it on the vertical gutter 22 and made to drain by feeding to the lower part in order together with the waterdrop flowed into the horizontal gutter 21. By this structure the waterdrop can be drained without narrowing the effective area of the lift passage and what is close to standard can be used for the lift passage instrument. Consequently the maintenance control is facilitated.