The present invention provides a surface-modified inorganic nitride having excellent dispersibility. Furthermore, the present invention provides a composition, a thermally conductive material, and a device with a thermally conductive layer which contain the surface-modified inorganic nitride. The surface-modified inorganic nitride of the present invention includes an inorganic nitride, and a compound which is represented by General Formula (1) and is adsorbed onto a surface of the inorganic nitride.