A method for manufacturing an integrated member and an integrated member manufactured by the method which can improve the joining strength and reduce the manufacturing cost. A method for manufacturing an integrated member by welding a first member formed of aluminum alloy material and a second member formed of ferrous-based material characterized in that the first member contains a predetermined amount of silicon and has a thickness larger than that of the second member. The second member can be pressed against the first member along the thickness direction, and by electrically energizing the pressed-in portion during the pressing period, electric resistance welding can be used. The pressing-in amount is set to a value larger than the thickness of the second member and less than that of the first member. The overlapping margin of the first and second members is set to a value of 0.5 mm or more.