Provided is a material that has excellent handleability and processability, and that when used as a support for a different material, enables support of the different material up to an inner part thereof. A carbon sheet contains one or more carbon nanotubes and has a porosity of not less than 5% and not more than 90%. The carbon sheet preferably includes: a porous substrate made from carbon; and the carbon nanotubes, attached to the porous substrate. The carbon nanotubes contained in the carbon sheet are preferably single-walled carbon nanotubes. Moreover, the carbon nanotubes contained in the carbon sheet preferably have a nitrogen adsorption specific surface area of 600 m2/g or more.