Provided is a substrate hydrophilizing agent that improves the wettability of a substrate surface with respect to a photoresist. A substrate hydrophilizing agent of the present invention is an agent for hydrophilizing a surface of a substrate on which a pattern is formed through photolithography, and contains at least the following Component (A) and Component (B).
Component (A): a water-soluble oligomer having a weight average molecular weight from 100 to less than 10000.
Component (B): water.
The water-soluble oligomer of Component (A) is preferably a compound represented by the following Formula (a-1):

Ra1O—(C3H6O2)n—H  (a-1)

(where Ra1 represents a hydrogen atom, a hydrocarbon group which may have a hydroxyl group, or an acyl group; and n is an integer from 2 to 60.)