To provide a cleaning solution for a substrate for a semiconductor device capable of removing particle contamination, organic contamination and metal contamination at the same time without corroding the substrate surface, and further having good water rinsability and capable of making the substrate surface highly clean in a short time, and a cleaning method. A cleaning solution for a substrate for a semiconductor device, which comprises an organic acid as component (a), an organic alkaline component as component (b), a surfactant as component (c) and water as component (d) and which has a pH of at least 1.5 and less than 6.5. A method for cleaning a substrate for a semiconductor device, which comprises cleaning a substrate for a semiconductor device having a Cu film and a low dielectric constant insulating film on its surface and having CMP treatment applied thereto, by means of the above cleaning solution for a substrate for a semiconductor device.