A light source apparatus 20 includes a first rotational filter section 23 that can place a blue filter 23a, a green filter 23b and a magenta filter 23c in a light path LP, a second rotational filter section 24 that can place a yellow filter 24a in the light path and a band selection filter section 22 that can place an NBI filter that limits blue and green light to a narrow band, wherein the first and the second rotational filter sections 23, 24 are controllable so that in the case of normal light imaging, the yellow filter 24a is placed in the light path LP when the magenta filter 23c is placed in the light path LP and in the case of narrow band imaging, the NBI filter is placed in the light path LP and the yellow filter 24a is placed in the light path LP when the green filter 23b is placed in the light path LP.
