A liquid discharge head comprising: a discharge port member having a discharge port configured to discharge a liquid, wherein the discharge port member is made of a product of curing of a photosensitive resin composition comprising: (a) a compound polymerizable in the presence of an acid; and (b) a photoacid generating agent comprising an onium salt having a cationic part structure represented by formula below and an anionic part structure represented by formula below, wherein the component (b) absorbs at least 50% of the amount of 365 nm wavelength light absorbed by the photosensitive resin composition, wherein R 1 to R 3 each independently represent an organic group of 1 to 30 carbon atoms, the structures represented by R 1 to R 3 together contain at least two oxygen atoms and comprise at least one organic group selected from a thioxanthone skeleton, a 9,10-dialkoxyanthracene skeleton, or an anthraquinone skeleton, X is selected from a carbon atom, a nitrogen atom, a phosphorus atom, a boron atom, and an antimony atom, Y is at least one selected from -S(=O) 2 -, -CF 2 -O-, -CF 2 -C(=O)-, -CF 2 -C(= O)-O-, and -CF 2 -O-C(=O)-, or X and R 4 are directly bonded to each other, R 4 represents a hydrocarbon group of 1 to 30 carbon atoms, provided that when Y represents -S(=O) 2 - or a single bond, the hydrocarbon group represented by R 4 has at least one fluorine atom, and when X represents a carbon atom, m and n represent integers that satisfy m + n = 3 and n = 0 to 2, when X represents a nitrogen atom, m and n represent integers that satisfy m + n = 2 and n = 0 to 1, when X represents a phosphorus or antimony atom, m and n represent integers that satisfy m + n = 6 and n = 0 to 6, or when X represents a boron atom, m and n represent integers that satisfy m + n = 4 and n = 0 to 3. a discharge port member having a discharge port configured to discharge a liquid, wherein the discharge port member is made of a product of curing of a photosensitive resin composition comprising: (a) a compound polymerizable in the presence of an acid; and (b) a photoacid generating agent comprising an onium salt having a cationic part structure represented by formula below and an anionic part structure represented by formula below, (a) a compound polymerizable in the presence of an acid; and (b) a photoacid generating agent comprising an onium salt having a cationic part structure represented by formula below and an anionic part structure represented by formula below, wherein the component (b) absorbs at least 50% of the amount of 365 nm wavelength light absorbed by the photosensitive resin composition, wherein R 1 to R 3 each independently represent an organic group of 1 to 30 carbon atoms, the structures represented by R 1 to R 3 together contain at least two oxygen atoms and comprise at least one organic group selected from a thioxanthone skeleton, a 9,10-dialkoxyanthracene skeleton, or an anthraquinone skeleton, X is selected from a carbon atom, a nitrogen atom, a phosphorus atom, a boron atom, and an antimony atom, Y is at least one selected from -S(=O) 2 -, -CF 2 -O-, -CF 2 -C(=O)-, -CF 2 -C(= O)-O-, and -CF 2 -O-C(=O)-, or X and R 4 are directly bonded to each other, R 4 represents a hydrocarbon group of 1 to 30 carbon atoms, provided that when Y represents -S(=O) 2 - or a single bond, the hydrocarbon group represented by R 4 has at least one fluorine atom, and when X represents a carbon atom, m and n represent integers that satisfy m + n = 3 and n = 0 to 2, when X represents a nitrogen atom, m and n represent integers that satisfy m + n = 2 and n = 0 to 1, when X represents a phosphorus or antimony atom, m and n represent integers that satisfy m + n = 6 and n = 0 to 6, or when X represents a boron atom, m and n represent integers that satisfy m + n = 4 and n = 0 to 3.