A bellows comprising: a first flat part having a flat cylindrical shape; a second flat part having a flat cylindrical shape and disposed opposite to the first flat part; and a plurality of corrugated portions, wherein each of the corrugated portions has a tweezers shape and is disposed between the first flat part and the second flat part, and the plurality of corrugated portions are sequentially connected to each other, characterized in that each corrugated portion comprises: a protrusion portion having a first surface and a second surface successively provided next to the first surface in parallel, in which the first surface and the second surface are in close contact with each other, and a connecting portion of the first surface and the second surface protrudes in a circular shape; a convex portion having a third surface extending from the first surface and protruding outward in a convex shape and a fourth surface extending from the second surface and protruding outward in a convex shape; and a concave portion having a fifth surface extending from the third surface and recessed inward in a concave shape and a sixth surface extending from the fourth surface and recessed inward in a concave shape, and the corrugated portions are connected to each other at the concave portion. a first flat part having a flat cylindrical shape; a second flat part having a flat cylindrical shape and disposed opposite to the first flat part; and a plurality of corrugated portions, wherein each of the corrugated portions has a tweezers shape and is disposed between the first flat part and the second flat part, and the plurality of corrugated portions are sequentially connected to each other, characterized in that each corrugated portion comprises: a protrusion portion having a first surface and a second surface successively provided next to the first surface in parallel, in which the first surface and the second surface are in close contact with each other, and a connecting portion of the first surface and the second surface protrudes in a circular shape; a convex portion having a third surface extending from the first surface and protruding outward in a convex shape and a fourth surface extending from the second surface and protruding outward in a convex shape; and a concave portion having a fifth surface extending from the third surface and recessed inward in a concave shape and a sixth surface extending from the fourth surface and recessed inward in a concave shape, and the corrugated portions are connected to each other at the concave portion. a protrusion portion having a first surface and a second surface successively provided next to the first surface in parallel, in which the first surface and the second surface are in close contact with each other, and a connecting portion of the first surface and the second surface protrudes in a circular shape; a convex portion having a third surface extending from the first surface and protruding outward in a convex shape and a fourth surface extending from the second surface and protruding outward in a convex shape; and a concave portion having a fifth surface extending from the third surface and recessed inward in a concave shape and a sixth surface extending from the fourth surface and recessed inward in a concave shape, and the corrugated portions are connected to each other at the concave portion.