[Problem] To provide a compound useful as a drug for preventing and/or treating kidney disease. [Solution] The inventors studied compounds having trypsin-inhibiting activity, confirmed that guanidinobenzoic acid ester compounds have trypsin-inhibiting activity, and completed the invention. These guanidinobenzoic acid ester compounds can be used as drugs for the prevention and/or treatment of kidney disease (for example, chronic kidney disease, acute glomerulonephritis, acute renal failure, and the like) as alternative drugs to a low-protein diet, and/or as drugs for the prevention and/or treatment of diseases in which trypsin participates (for example, chronic pancreatitis, reflux esophagitis, hepatic encephalopathy, influenza, and the like).
