A condensation-curable silicone resin composition sheet, comprising: organopolysiloxane having a weight average molecular weight of 5,000 or more and 1,000,000 or less in terms of polystyrene and measured by chromatography according to the conditions mentioned in the description, and being in a plastic solid state or a semi-solid state at ordinary temperature, with the molecule having at least two silicon atom-bonded alkoxy groups or silicon atom-bonded hydroxy groups, shown by the following formula: (R 1 3 SiO 1/2) a' (R 1 2 SiO 2/2) b' (R 2 SiO 3/2) c' (SiO 4/2) d' (OR 3) e' wherein each R 1 independently represents a hydrogen atom, a monovalent aliphatic hydrocarbon group having 1 to 6 carbon atoms, or an aromatic hydrocarbon group having 6 to 12 carbon atoms; R 2 represents a monovalent aliphatic hydrocarbon group having 1 to 6 carbon atoms or an aromatic hydrocarbon group having 6 to 12 carbon atoms; R 3 represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkoxyalkyl group having 2 to 6 carbon atoms; each of "a'", "b'", "c'", and "d'" is an integer of 0 or more; "e'" is an integer of 2 or more; and b'+c'+d' is an integer of 1 or more; and organopolysiloxane having a molecular weight of 10,000 or more and 1,000,000 or less in terms of polystyrene, as measured by chromatography according to the conditions mentioned in the description, with the molecule having at least two silicon atoms, each of which has one hydrogen atom and two alkoxy groups or hydroxy groups, shown by the following formula: (R 1 3 SiO 1/2) a (R 1 2 SiO 2/2) b (R 2 SiO 3/2) c (SiO 4/2) d (OR 3) e (HSi(OR 3) 2 O 1/2) f wherein, R 1, R 2 and R 3 have the same meanings as described above, each of "a", "b", "c", "d", and "e" is an integer of 0 or more; c+d is an integer of 2 or more; and "f" is an integer of 2 or more; wherein the condensation-curable silicone resin composition sheet is in a plastic solid state or a semi-solid state at ordinary temperature and comprises the component in an amount of 5 to 100 parts by mass based on 100 parts by mass of the component. organopolysiloxane having a weight average molecular weight of 5,000 or more and 1,000,000 or less in terms of polystyrene and measured by chromatography according to the conditions mentioned in the description, and being in a plastic solid state or a semi-solid state at ordinary temperature, with the molecule having at least two silicon atom-bonded alkoxy groups or silicon atom-bonded hydroxy groups, shown by the following formula: (R 1 3 SiO 1/2) a' (R 1 2 SiO 2/2) b' (R 2 SiO 3/2) c' (SiO 4/2) d' (OR 3) e' wherein each R 1 independently represents a hydrogen atom, a monovalent aliphatic hydrocarbon group having 1 to 6 carbon atoms, or an aromatic hydrocarbon group having 6 to 12 carbon atoms; R 2 represents a monovalent aliphatic hydrocarbon group having 1 to 6 carbon atoms or an aromatic hydrocarbon group having 6 to 12 carbon atoms; R 3 represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkoxyalkyl group having 2 to 6 carbon atoms; each of "a'", "b'", "c'", and "d'" is an integer of 0 or more; "e'" is an integer of 2 or more; and b'+c'+d' is an integer of 1 or more; and organopolysiloxane having a molecular weight of 10,000 or more and 1,000,000 or less in terms of polystyrene, as measured by chromatography according to the conditions mentioned in the description, with the molecule having at least two silicon atoms, each of which has one hydrogen atom and two alkoxy groups or hydroxy groups, shown by the following formula: (R 1 3 SiO 1/2) a (R 1 2 SiO 2/2) b (R 2 SiO 3/2) c (SiO 4/2) d (OR 3) e (HSi(OR 3) 2 O 1/2) f wherein, R 1, R 2 and R 3 have the same meanings as described above, each of "a", "b", "c", "d", and "e" is an integer of 0 or more; c+d is an integer of 2 or more; and "f" is an integer of 2 or more; wherein the condensation-curable silicone resin composition sheet is in a plastic solid state or a semi-solid state at ordinary temperature and comprises the component in an amount of 5 to 100 parts by mass based on 100 parts by mass of the component.