Kit for cleaning agent and method for preparing cleaning agent

A kit for preparing a cleaning agent with a pH of 7.5 to 13.0 that is used in cleaning of a semiconductor substrate having undergone a chemical mechanical polishing process, the kit comprising:

• a first liquid containing a compound represented by Formula (1), an acidic compound and water and showing acidic properties;
• and
• a second liquid containing a basic compound and showing alkaline properties,
• wherein the basic compound comprises a hydroxylamine compound, and
• the basic compound further comprises at least one selected from the group consisting of a diamine compound, an amidine compound, an azole compound, a pyrazine compound, a pyrimidine compound, and a quaternary ammonium compound,
• where R1 to R5 each independently represent a hydrogen atom, a hydroxyl group, a carboxyl group, or an alkoxycarbonyl group, and at least two of R1 to R5 represent a hydroxyl group, provided that a combination in which R1 and R5 each represent a hydroxyl group, a combination in which R2 and R4 each represent a hydroxyl group, and a combination in which R3 and R5 each represent a hydroxyl group are excluded.