A maintenance liquid for use in maintenance of a device equipped with a discharge head for discharging an ultraviolet ray curable type composition containing an acyl phosphine oxide based photopolymerization initiator toward an attachment object comprising: a polymerizable compound in which a saturation solubility of an acyl phosphine oxide-based photopolymerization initiator at 20°C is equal to or greater than 5.0% by mass, wherein the polymerizable compound includes at least any one of: a vinyl ether group-containing (meth)acrylic acid ester represented by the following general formula CH 2 =CR 1 -COOR 2 -O-CH=CH-R 3; and a monofunctional (meth)acrylate compound having an aromatic ring, wherein in the formula, R 1 represents a hydrogen atom or a methyl group, R 2 represents a divalent organic residue having 2 to 20 carbon atoms, and R 3 represents a hydrogen atom or a monovalent organic residue having 1 to 11 carbon atoms, characterized in that the content of the vinyl ether group-containing (meth)acrylic acid ester, if present, is 15% by mass to 45% by mass with respect to the total amount of the maintenance liquid, and wherein the content of the monofunctional (meth)acrylate compound having an aromatic ring, if present, is 19.3% by mass to 40% by mass with respect to the total amount of the maintenance liquid. a polymerizable compound in which a saturation solubility of an acyl phosphine oxide-based photopolymerization initiator at 20°C is equal to or greater than 5.0% by mass, wherein the polymerizable compound includes at least any one of: a vinyl ether group-containing (meth)acrylic acid ester represented by the following general formula CH 2 =CR 1 -COOR 2 -O-CH=CH-R 3; and a monofunctional (meth)acrylate compound having an aromatic ring, wherein in the formula, R 1 represents a hydrogen atom or a methyl group, R 2 represents a divalent organic residue having 2 to 20 carbon atoms, and R 3 represents a hydrogen atom or a monovalent organic residue having 1 to 11 carbon atoms, characterized in that the content of the vinyl ether group-containing (meth)acrylic acid ester, if present, is 15% by mass to 45% by mass with respect to the total amount of the maintenance liquid, and wherein the content of the monofunctional (meth)acrylate compound having an aromatic ring, if present, is 19.3% by mass to 40% by mass with respect to the total amount of the maintenance liquid. a vinyl ether group-containing (meth)acrylic acid ester represented by the following general formula CH 2 =CR 1 -COOR 2 -O-CH=CH-R 3; and a monofunctional (meth)acrylate compound having an aromatic ring, wherein in the formula, R 1 represents a hydrogen atom or a methyl group, R 2 represents a divalent organic residue having 2 to 20 carbon atoms, and R 3 represents a hydrogen atom or a monovalent organic residue having 1 to 11 carbon atoms, characterized in that the content of the vinyl ether group-containing (meth)acrylic acid ester, if present, is 15% by mass to 45% by mass with respect to the total amount of the maintenance liquid, and wherein the content of the monofunctional (meth)acrylate compound having an aromatic ring, if present, is 19.3% by mass to 40% by mass with respect to the total amount of the maintenance liquid.