A silicone resin comprising constitutional units represented by formula (1) and having a Mw of 3,000-500,000 contains 10-50 wt % of (A-1) a first silicone resin having a silicone content of 10-40 wt % and (A-2) a second silicone resin having a silicone content of 50-80 wt %. A resin composition comprising the silicone resin can be formed in film form, and it possesses satisfactory covering or encapsulating performance to large size/thin wafers. The resin composition or resin film ensures satisfactory adhesion, low warpage, and wafer protection. The resin film is useful in wafer-level packages.