To reduce the assembly man-hour at site, and reduce the usage of decorative panels in a door in which the distance between a door hanger and a door body is special by lapping one end of an upper reinforcement of the door body on a decorative panel part, and projecting the other end upward of the decorative panel.

A door 3 is supported by a door hanger which is guided by a door rail 1 and moved in the horizontal direction, and a door shoe (a guide piece) provided on a lower part of the door 3 is moved in a groove of a sill. One end (a) part of an upper reinforcement member 6 on an upper part of the door 3 is lapped on the door 3, the other end (b) part is projected upward of the door 3 to connected an upper part 6a of the reinforcement member 6 to the door hanger 2. In a structure where the door is opened to examine an indicator making use of a lower space of the door rail 1, another member need not be used, and the assembly man-hour at site is not increased, and the decorative panel of the door need not be longer than required.