Curable polysilsesquioxane compound, production method thereof, curable composition, cured product and use method of curable composition

A curable polysilsesquioxane compound comprising at least one structural unit represented by CHR1X0-D-SiO3/2, wherein R1 is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, X0 is a cyano group, or a group represented by OG (wherein G is a protecting group for a hydroxyl group), and D is a single bond, or a substituted or unsubstituted divalent organic group having 1 to 20 carbon atoms,

• the curable polysilsesquioxane compound having a 29Si nuclear magnetic resonance spectrum that has a first peak top within a range of −73 ppm or more and less than −65 ppm, has a second peak top within a range of −82 ppm or more and less than −73 ppm, and a peak is not observed within the range of −65 ppm or more and less than −55 ppm, or, a ratio of the integral value of the peak within the range of −65 ppm or more and less than −55 ppm to the integral value of the peak within the range of −73 ppm or more and less than −65 ppm is less than 0.5% in the 29Si nuclear magnetic resonance spectrum.