An optical fiber amplifier (2) includes: a first pumping source (10); a second pumping source (20); an amplification optical fiber (3) in which an active element is doped; a first optical filter (15) coupled to the first pumping source (10) and one end of the amplification optical fiber (30), the first optical filter (15) transmitting a light at a wavelength the same as the wavelength of a first pumping light and reflecting a light at a wavelength the same as the wavelength of a second pumping light; and a second optical filter (25) coupled to the second pumping source (20) and the other end of the amplification optical fiber (3), the second optical filter (25) transmitting a light at a wavelength the same as the wavelength of the second pumping light and reflecting a light at a wavelength the same as the wavelength of the first pumping light.