To enable a partition wall to be easily removed even after it is assembled by a method wherein a packing member having resiliency is fixed in advance to a pushing edge in a vertical or a lateral direction to fix a wall part, a connecting leg at the pushing edge is inserted into a connecting hole of a beam, the beam is fixed and the wall part is pushed with the packing.

There is provided a plate-like wall part 38 for closing a space enclosed by a casing formed by right and left stiles and up- and down-rails. There are provided the right and left beads 39 in vertical direction for pushing a circumferential edge of the wall 38 and up- and down-beads 40 in a lateral direction. These beads 39, 40 are fixed to the casing with a pair of connecting legs 49, 50 being inserted into connecting holes 45 of the vertical beam 34 at the casing. At this time, a packing 52 having a resiliency such as rubber or the like is fixed to each of the pushing edges 39, 40 in advance and then both edges 54 of the wall part 38 are pushed by the packing 52. With such an arrangement as above, it is possible to remove the partition wall 9 easily even after assembling operation.