PURPOSE: To improve holding stability for glass and its appearance, and also to, favorably drain water.

CONSTITUTION: In a curtain wall having construction for supporting an external wall with structural members composed of mullions 1 and transoms 2, the transoms 2 are spacedly arranged in the horizontal direction on the position of a vertical joint on the indoor side of the position nearly in response to a horizontal joint. A catch pan 80 covering the gap in the horizontal direction is ridingly provided so as to place the bottom wall on the upper face between the adjoining transoms. In the catch pan 80, the flowing down port of a gutter constituted of the gutter wall and the bottom wall is communicated to the vertical joint constituted of the lock member of an adjacent integrated panel and the lock member of the other integrated panel.