A heat dissipating member which is disposed between a heat generating electronic component which when operated generates heat and reaches a temperature higher than room temperature and a heat dissipating component is characterized in that the heat dissipating member is non-fluid in a room temperature state prior to operation of the electronic component and acquires a low viscosity, softens or melts under heat generation during operation of the electronic component to fluidize at least a surface thereof so as to fill between the electronic component and the heat dissipating component without leaving any substantial voids, and the heat dissipating member is formed of a composition comprising a silicone resin and a heat conductive filler.