A fluorescent probe for detecting pancreatic fluid containing a compound or salt thereof represented by formula (I) below. (In the formula, A represents an amino acid residue or N-substituted amino acid residue, with A forming an amide bond with the adjacent NH in the formula; R1 represents a hydrogen atom or 1 to 4 same or different substituent groups that bond with a benzene ring; R2, R3, R4, R5, R6, and R7 each independently represent a hydrogen atom, a hydroxyl group, an alkyl group, or a halogen atom; R8 and R9 each independently represent a hydrogen atom or an alkyl group; and X represents a C1-C3 alkylene group).