A method of manufacturing a heat conductive sheet comprising strips joined together side-by-side, each strip comprising a resin and a carbon material having a number-based modal diameter of 5 μm to 50 μm and comprising a particulate carbon material, wherein the heat conductive sheet has heat conductivity in thickness direction of 40 W/m·k or more, wherein the number-based modal diameter of the carbon material refers to a particle diameter corresponding to the maximum in a particle size distribution curve of the carbon material, which is a plot of carbon material count versus particle diameter, as measured for a suspension containing the carbon material using a laser diffraction/scattering particle size analyzer, the method comprising: mixing a particulate carbon material having a first particle diameter and a resin to provide a composition; shaping the composition into a sheet by pressure application to provide a pre-heat conductive sheet containing the particulate carbon material having a second particle diameter and the resin; obtaining a laminate either by laminating the pre-heat conductive sheets on top of each other or by folding or rolling the pre-heat conductive sheet; and slicing the laminate at an angle of 45° or less relative to the lamination direction to provide a heat conductive sheet which comprises strips joined together side-by-side, each strip comprising the carbon material having the second particle diameter and the resin, characterised in that the particulate carbon material is subjected to a particle size change as a result of being disintegrated in the pre-heat conductive sheet forming step, such that the second particle diameter is a number-based modal diameter which is 5 μm to 50 μm and is smaller than the first particle diameter. wherein the heat conductive sheet has heat conductivity in thickness direction of 40 W/m·k or more, wherein the number-based modal diameter of the carbon material refers to a particle diameter corresponding to the maximum in a particle size distribution curve of the carbon material, which is a plot of carbon material count versus particle diameter, as measured for a suspension containing the carbon material using a laser diffraction/scattering particle size analyzer, the method comprising: mixing a particulate carbon material having a first particle diameter and a resin to provide a composition; shaping the composition into a sheet by pressure application to provide a pre-heat conductive sheet containing the particulate carbon material having a second particle diameter and the resin; obtaining a laminate either by laminating the pre-heat conductive sheets on top of each other or by folding or rolling the pre-heat conductive sheet; and slicing the laminate at an angle of 45° or less relative to the lamination direction to provide a heat conductive sheet which comprises strips joined together side-by-side, each strip comprising the carbon material having the second particle diameter and the resin, characterised in that the particulate carbon material is subjected to a particle size change as a result of being disintegrated in the pre-heat conductive sheet forming step, such that the second particle diameter is a number-based modal diameter which is 5 μm to 50 μm and is smaller than the first particle diameter. mixing a particulate carbon material having a first particle diameter and a resin to provide a composition; shaping the composition into a sheet by pressure application to provide a pre-heat conductive sheet containing the particulate carbon material having a second particle diameter and the resin; obtaining a laminate either by laminating the pre-heat conductive sheets on top of each other or by folding or rolling the pre-heat conductive sheet; and slicing the laminate at an angle of 45° or less relative to the lamination direction to provide a heat conductive sheet which comprises strips joined together side-by-side, each strip comprising the carbon material having the second particle diameter and the resin, characterised in that the particulate carbon material is subjected to a particle size change as a result of being disintegrated in the pre-heat conductive sheet forming step, such that the second particle diameter is a number-based modal diameter which is 5 μm to 50 μm and is smaller than the first particle diameter.