A carbon fiber nonwoven fabric in which carbon fibers are sized with an aliphatic compound having a plurality of epoxy groups or a specific aromatic compound; the number average x of carbon fibers forming a carbon fiber bundle, in which the number of carbon fibers forming the carbon fiber bundle is 90 or more, is 90 to 1,000 fibers per bundle among the carbon fiber bundles in the carbon fiber nonwoven fabric; and the standard deviation σ of the number of carbon fibers forming the carbon fiber bundle is 50 to 500.