Thermally conductive sheet, cured product thereof, and semiconductor device

A thermally conductive sheet includes a thermosetting resin and an inorganic filler material dispersed in the thermosetting resin. Measuring a pore diameter distribution through mercury intrusion technique for the inorganic filler material included in an incineration residue after a cured product of the thermally conductive sheet is heated and incinerated at 700 DEG C. for four hours, a porosity of the inorganic filler material represented as 100b/a is greater than or equal to 40% and less than or equal to 65% given that a is the volume of particles of the inorganic filler material included in the incineration residue, and b is the volume of voids in the particles of the inorganic filler material included in the incineration residue. An average pore diameter of the inorganic filler material included in the incineration residue is greater than or equal to 0.20 [mu]m and less than or equal to 1.35 [mu]m.