To provide a carbon fiber felt which reduces a pressure loss when an electrolyte is passed through an electrode, has adequate liquid permeability in a thickness direction, and is used as a material for an electrode having excellent conductivity.

A carbon fiber felt 2 has a concavo-convex shape comprising a plurality of ridge parts 4 which are formed on at least one face of the carbon fiber felt 2 so as to protrude toward the outside in a belt-like shape, and groove parts 6 which are formed between the plurality of ridge parts 4. A bulk density of a felt in the ridge part 4 is higher than a bulk density of a felt constituting a bottom wall 8 of the groove part. It is preferable that the groove 6 is formed on a surface of the felt so as to have a linear shape, a lattice shape, a diamond shape or a wavy shape.