The invention discloses a modified silica particles and a manufacture method, thin coating liquid for film formation, a base material with the thin film and a photoelectric unit. The thin film is manufactured by using the silicon dioxide particles having the organosilicon compound which is contained on the surface and has four function groups; the oligomer molecular weight is 1000-10000 and the form after the combination of the monomers. The acid resistance capability of the silicon dioxide particle of the oligomer, the surface of which combines with four function groups, is high. The thin film containing the silicon dioxide is high in density and temperature resistance. Besides, the thin film is used as an adhesive and an organosilicon compound using the four function group. The organosilicon constituting the oligomer and the organisilicon having the adhesive component can be identical compound and different compound. Particularly the particles with low refractive rate can be made for the reflective film.
