Provided are a negative photosensitive resin composition, a partition wall having high light-shielding properties formed by curing the photosensitive composition, and an optical element having the partition wall, the negative photosensitive resin composition being capable of producing A
black matrix containing a
high concentration of pigments, high light-shielding properties, high resolubility, no defects in the
coating film obtained by the slit
coating method, and has a
viscosity that can be applied by the slit
coating method. A negative photosensitive resin composition, the negative photosensitive resin composition comprises an alkali-soluble resin, a photopolymerization initiator, a black colorant and a
solvent, the content of the black colorant relative to the
total solid content of the composition exceeds 20% by
mass, the
solvent contains a compound represented by R1O(C2H4O)2R2 (R1 represents a
methyl group, and R2 represents an
alkyl group with 2 or 3 carbon atoms.) in a ratio of 20 to 100% by
mass relative to the total amount of the
solvent, And a partition wall formed of the cured film, the partition wall is formed to partition the surface of the substrate into a plurality of divisions for pixel formation.