A brassiere (1) which can be disassembled and is capable of size adjustment. It comprises: a pair of frames (4) which are swingably connected to each other and which are made of an elastic material constituted of first, second, and third framing materials (9 and 10) capable of length adjustment; a pair of covering materials (5) with which the pair of frames (4) are covered to form a pair of cups (2 and 3); and a pair of arms with which the pair of frames (4) are separably connected to each other. The brassiere (1) further includes: a cup-connecting member (6) one end of which is pivotally supported so as to be capable of being tightly fastened; a breast band (7) capable of length adjustment which has a pair of hooking parts (7a and 7b) which can be fastened and unfastened; and a band-connecting member (8) which is separably connected to the outer end of each frame (4) and to which an end of the breast band (7) is connected.