Chair

The present invention provides an unconventional chair capable of smoothly performing the action of a seat using a rolling surface. The chair is configured in such a manner that the upper base portion (31), which is at least one of the upper base portion (31) and the lower base portion (32) that face each other, has a curved rolling surface (312a), and the seat (1) provided on the upper base portion (31) is swung by rolling the upper base portion (31) with respect to the lower base portion (32), in which regions having different curvatures exist in a part of the rolling surface (312a), and in which the upper base portion (31) and the lower base portion (32) face each other. An elastic member (33) is interposed between the region and a corresponding region of the counterpart. 本发明提供能够顺畅地进行利用了滚动面的座的动作的以往没有的椅子。所述椅子构成为，互相相对的上侧基部(31)和下侧基部(32)中的至少一方即上侧基部(31)具有弯曲的滚动面(312a)，通过使上侧基部(31)相对于下侧基部(32)滚动，从而使设置于上侧基部(31)的座(1)摆动，其中，在滚动面(312a)的一部分存在曲率不同的区域，使弹性构件(33)介于该区域与对方的对应的区域之间。