To provide a ladies' undergarment exerting tightening effect uniformly on parts necessary to be tightened, excellent in air permeability and reduced in oppressive feeling and tightened feeling.

The ladies' undergarment is formed of elastic knitted fabric knitted from continuous fibers, and has a belt-like tightening part which is positioned around the waist. The tightening part is provided so as to be formed into an almost M shape on the front side of the undergarment when worn, and at least a gusset part of the undergarment has a mesh form.