Photoresist composition for black matrix, and black matrix wherein the photoresist composition for a black matrix can form a black matrix whose surface resistance value does not decrease even after post-baking at a high temperature for a long time

The present invention provides a photoresist composition for a black matrix, which can form a black matrix whose surface resistance value does not decrease even after post-baking at a high temperature for a long time. The present invention relates to a photoresist composition for a black matrix, comprising a black colorant, an alkali-soluble resin having a carboxyl group, a photopolymerization initiator, an organic solvent, and an oxazine compound. The oxazine compound is the compound represented by the following general formula (1) and /or (2). In the general formula (1), R1 and R2 represent an alkyl or aryl group having an unsaturated bond and are the same or different from each other, where X1 represents any one of the link bases represented by the following formula (3)~ (5). In the general formula (2), R3 and R4 represent an alkyl or aryl group having an unsaturated bond and are the same or different from each other, where X2 is a divalent link base.