Provided is an electrode mixture layer capable of reducing internal resistance by use of a carbon nanotube molding. The electrode mixture layer includes an active material and a conductor of carbon nanotubes in close contact with the surface of the active material, and the number density of the carbon nanotubes is 4 tubes/μm or more. The number density is defined as a value obtained by providing measurement lines on a scanning electron microscope image of a surface of the electrode mixture layer at 0.3 μm intervals both longitudinally and laterally, measuring the total number of the carbon nanotubes being in close contact with the surface of the active material and intersecting the measurement lines, and dividing the total number of the carbon nanotubes by the total length of the measurement lines on the active material surface.