(EN) An object of the present invention is to provide an electro-deposited copper foil far excellent in physical properties after heating at high-temperature than the conventional- electro-deposited copper foils and is suitable for usage as a negative electrode current collector of a lithium ion secondary battery. An electro-deposited copper foil- having tensile strength as received of 600 MPa or more and tensile strength after heating at 350 deg.-C for t hour of 410 MPa or more is employed to achieve the object. Moreover, a sulfuric acid based copper electrolytic solution containing polyethyleneimine having a molecular weight of 10000 to 70000 in concentration of 20 mg/L to 100 mq/l and a chloride ion in concentration of 0.5 mg/l, to 2.5 mg/L is used in a method of manufacturing the electrodeposited copper foil.
