PURPOSE: To provide a deinking liquid excellent in cleaning ability, useful for copied toner images, consisting of a homogeneous mixture composed of a glycol- based acetate, alkylene glycol dialkyl ether, glycol-based monoether and water.

CONSTITUTION: This deinking liquid consists of a homogeneous mixture composed of 30-80wt.% of at least one kind of compound selected from glycol-based acetates of formula, CH3COO(CH2CH2O)nR1 ((n) is a natural number of 2-4; R1 is methyl or ethyl) and alkylene glycol dialkyl ethers of formula, R2O(CH2 CH2O)nR3 ((n) is a natural number of 2-5; R2 and R3 are each a ≤3C alkyl), 10-55wt.% of a glycol-based monoether of formula, R4(CH2CH2O)nH ((n) is a natural number of 2-4; R4 is a 3C or 4C alkyl), and 10-30wt.% of water. A cleaning is made by the following method: plastic films such as OHP sheets with copied toner images developed and set on are immersed in this deinking liquid and then dried.