The present invention provides methods of manufacturing a condensation-curable silicone resin composition sheet that is in a plastic solid state or a semi-solid state at ordinary temperature, including: (A) organopolysiloxane having a weight average molecular weight of 5,000 or more and 1,000,000 or less in terms of polystyrene shown by the following formula (1): (R13SiO1/2)a′(R12SiO2/2)b′(R2SiO3/2)c′(SiO4/2)d′(OR3)e′  (1); together with (B) organopolysiloxane having a molecular weight of 10,000 or more and 1,000,000 or less in terms of polystyrene shown by the following formula (2): (R13SiO1/2)a(R12SiO2/2)b(R2SiO3/2)c(SiO4/2)d(OR3)e(HSi(OR3)2O1/2)f   (2) in an amount of 5 to 100 parts by mass based on 100 parts by mass of the component (A). This condensation-curable silicone resin composition sheet is easy to be handled and has high heat resistance and ultraviolet light resistance while being excel in curing characteristics.