PURPOSE: To provide the title agent capable of obtaining in high recycling rate high-quality pulp of high whiteness with little residual ink, having high ink-removing ability irrespective of the type of printed waste paper.

CONSTITUTION: The objective deinking agent containing a reaction product obtained by addition reaction of an alkylene oxide to a mixture of (A) natural fatty oil and (B) an amine compound having two or more active hydrogens at the molar ratio of (1:0.1)-(1:1).