PURPOSE: To deink a waste paper in such a manner as to be able to readily handle and to suitably provide regenerated pulp having high brightness from the waste paper and in excellent operating properties at ambient temperature by using licinolic acid or oligomer thereof as a deinking agent.

CONSTITUTION: In a process carrying out a deinking by treating a waste paper with a deinking chemical, the waste paper is deinked by using licinolic acid and/or oligomer thereof as the deinking agent. Furthermore, the deinking agent contains preferably licinolic acid and/or oligomer thereof at an amount of 10-95wt.%.