The below-mentioned formula (IA) or (IB) (R1 to show the electronic absorption characteristic substituent, as for R2 and R3 showing the hydrogen atom or the halogen atom R4 and R5 the hydrogen atom, shows the alkyl carbonyl group, or the alkyl carbonyl oxy methyl group, R6 shows the hydrogen atom or the alkyl group) with the chemical compound which is displayed or the reagent for hydrogen peroxide measurement which includes that salt, and the said chemical compound or that salt.下記の式(IA)又は(IB)(R1は電子吸引性置換基を示し、R2及びR3は水素原子又はハロゲン原子を示し;R4及びR5は水素原子、アルキルカルボニル基、又はアルキルカルボニルオキシメチル基を示し、R6は水素原子又はアルキル基を示す〕で表される化合物又はその塩、及び該化合物又はその塩を含む過酸化水素測定用試薬。
