Carbon fiber and method for producing the same

A carbon fiber derived from an acrylamide-based polymer fiber, wherein

• the acrylamide-based polymer is at least one selected from the group consisting of a homopolymer of an acrylamide-based monomer and a copolymer of an acrylamide-based monomer having a content of an acrylamide-based monomer units of 40 mol % or more and 99.9 mol % or less,
• an average fiber diameter of a single fiber is in a range of 3 to 10 μm, and
• an average value of an intensity ratio (D/G) of a D peak to a G peak in a Raman spectrum in a cross section perpendicular to a fiber axis direction of the single fiber is 0.90 or less in a region inside a circle having a diameter of 1 μm and centered at a center of gravity of the cross section of the single fiber, and is 0.90 or less in a region up to 1 μm inside from an outer periphery of the cross section of the single fiber, wherein the D peak is observed at around 1360 cm−1 and derived from a defect in a graphite structure and the G peak is observed at around 1590 cm−1 and derived from the graphite structure.