The present invention provides a micromachining surface treatment material for and a surface treatment method that suppress widening of the diameter of contact holes when removing a natural oxidation layer arising at bottom sections of the contact holes. The micromachining surface treatment material contains less than 0.1% hydrofluoric acid, and more than 40% by weight but less than or equal to 47% by weight of ammonium fluoride. Also, a surfactant is contained therein in an amount from 0.0001 to 0.1% by weight.