Microprocessing treatment agent and microprocessing treatment method

A micromachining processing agent for micromachining an object to be processed having at least a silicon-containing insulating film, the micromachining processing agent consisting of:

• a compound represented by a chemical formula (1) below;
• hydrogen fluoride;
• ammonium fluoride;
• and
• water,
• wherein Rf represents perfluoroalkyl group having 1 to 4 carbon atoms, and M+ represents a hydrogen ion or an ammonium ion,
• wherein a content of the compound is 0.001 mass % or more and 0.5 mass % or less with respect to a total mass of the micromachining processing agent,
• a content of the hydrogen fluoride is 0.05 mass % or more and 25 mass % or less with respect to the total mass of the micromachining processing agent,
• a content of the ammonium fluoride is 0.5 mass % or more and 40 mass % or less with respect to the total mass of the micromachining processing agent, and
• the content of the hydrogen fluoride and the content of the ammonium fluoride satisfy a relational expression (1) below:
• [
• Mathematical
• ⁢
• Formula
• ⁢
• 1
• ]
• Y
• ≦
• -
• 0.
• ⁢
• 8
• ⁢
• X
• +
• 4
• ⁢
• 0
• (
• 1
• )
• wherein X represents a concentration (mass %) of hydrogen fluoride and Y represents a concentration (mass %) of ammonium fluoride.