A method of manufacturing an optical semiconductor apparatus, comprising the steps of: disposing a UV-curable adhesive silicone composition sheet on a surface of an optical semiconductor device; irradiating UV-rays to the UV-curable adhesive silicone composition sheet via a mask according to lithography; developing an uncured portion of the UV-curable adhesive silicone composition sheet with a solvent; and heat-curing after that, wherein the UV-curable adhesive silicone composition sheet is obtained by forming a UV-curable adhesive silicone composition into sheet-form, the UV-curable adhesive silicone composition comprises: an organopolysiloxane having a resin structure consisting of R 1 SiO 3/2, R 2 2 SiO 2/2, and R 3 a R 4 b SiO (4-a-b)/2 units, wherein, R 1, R 2 and R 3 each independently represent any one of a hydroxyl group, a methyl group, an ethyl group, a propyl group, a cyclohexyl group, and a phenyl group, R 4 represents a vinyl group or an allyl group, a represents 0, 1 or 2, b represents 1, 2 or 3, and a + b represents 2 or 3, wherein at least a part of R 2 2 SiO 2/2 units is continuously repeated and the number of repetitions thereof is 5 to 300, an organohydrogenpolysiloxane having a resin structure consisting of R 1 SiO 3/2, R 2 2 SiO 2/2, and R 3 c H d SiO (4-c-d)/2 units, wherein R 1, R 2 and R 3 each independently represent the same as that described above, c represents 0, 1 or 2, d represents 1 or 2, and c + d represents 2 or 3, wherein at least a part of R 2 2 SiO 2/2 units is continuously repeated and the number of repetitions thereof is 5 to 300, and a photoactive catalyst, and the UV-curable adhesive silicone composition is in a plastic solid state or a semi-solid state in an uncured state at room temperature, wherein "semi-solid" means a state that does not have the fluidity while having the plasticity and shows a liquid or solid property depending on an external stress. disposing a UV-curable adhesive silicone composition sheet on a surface of an optical semiconductor device; irradiating UV-rays to the UV-curable adhesive silicone composition sheet via a mask according to lithography; developing an uncured portion of the UV-curable adhesive silicone composition sheet with a solvent; and heat-curing after that, an organopolysiloxane having a resin structure consisting of R 1 SiO 3/2, R 2 2 SiO 2/2, and R 3 a R 4 b SiO (4-a-b)/2 units, wherein, R 1, R 2 and R 3 each independently represent any one of a hydroxyl group, a methyl group, an ethyl group, a propyl group, a cyclohexyl group, and a phenyl group, R 4 represents a vinyl group or an allyl group, a represents 0, 1 or 2, b represents 1, 2 or 3, and a + b represents 2 or 3, wherein at least a part of R 2 2 SiO 2/2 units is continuously repeated and the number of repetitions thereof is 5 to 300, an organohydrogenpolysiloxane having a resin structure consisting of R 1 SiO 3/2, R 2 2 SiO 2/2, and R 3 c H d SiO (4-c-d)/2 units, wherein R 1, R 2 and R 3 each independently represent the same as that described above, c represents 0, 1 or 2, d represents 1 or 2, and c + d represents 2 or 3, wherein at least a part of R 2 2 SiO 2/2 units is continuously repeated and the number of repetitions thereof is 5 to 300, and a photoactive catalyst,