To provide an alkaline cleaning composition for metal that shows both of high detergency and excellent rust prevention of a metal plate, e.g. a copper plate or the like.

The alkaline cleaning composition comprises an alkali agent, a rust-preventive agent and 0.01-0.5 wt.% of a chelate compound wherein the concentration of the alkali agent (a) in wt.% and the concentration of the rust- preventive (b) in wt.% satisfy the following formula (1):-0.95≤0.333a-25b-0.2≤0.09.