Treatment liquid and pattern forming method

A rinsing liquid for patterning a resist film,

• used for subjecting a resist film obtained from an actinic ray-sensitive or radiation-sensitive resin composition to washing, and
• containing an organic solvent,
• wherein the rinsing liquid contains a first organic solvent having a solubility parameter value of 16.3 MPa1/2 or less and a second organic solvent having a solubility parameter value of 17.1 MPa1/2 or more,
• the first organic solvent is undecane,
• the second organic solvent contains at least one solvent selected from the group consisting of butyl acetate and 2-heptanone as a major component, and at least one solvent selected from the group consisting of propylene glycol monomethyl ether acetate and propylene glycol monomethyl ether as a minor component,
• a content of the undecane is 40% by mass or less with respect to a total mass of the rinsing liquid, and
• the rinsing liquid does not include a polymer.