The invention belongs to the technical field of chemical products, and particularly relates to a cleaning agent. The cleaning agent comprises components as follows: 25%-40% of a stabilizer, 3%-10% of a chelating agent, 2%-10% of a penetrating agent, 1%-4% of a surfactant, 1%-5% of a dispersing agent and the balance of water. Compared with the prior art, the cleaning agent can thoroughly clean up foreign matters such as solid powder, organic matters, greasy dirt, fingerprints, various greases, abrasives, dust, dirt and the like on optical glass, plate glass, plexiglass, a mobile phone lens, a camera lens, glass lenses, sapphire glass, a ceramic wafer and a quartz optical product once, doesn't corrode surfaces of the optical glass, the plate glass, the plexiglass, the mobile phone lens, the camera lens, the glass lenses, the sapphire glass, the ceramic wafer, the quartz optical product and the like, and is not left over the surfaces.