An OPCPA apparatus of the present invention includes an optical pulse stretcher (100) for temporally stretching laser light, and applying short-wavelength preceding-type chirping. Pump lasers (210, 220) emit pump laser light. A first OPA unit (310) receives the pump laser light, and a signal having passed through the optical pulse stretcher, amplifies the signal, and generates a first idler. A first optical signal separation unit (410) separates output light of the first OPA unit into the first idler and remaining light (pump and signal). A second OPA unit (320) receives the first idler and another pump laser light, amplifies the first idler, and generates a second idler. A second optical signal separation unit (420) separates output light of the second optical parametric amplification unit into an amplified first idler and remaining light (pump and second idler). An optical pulse compressor (600) temporally compresses the amplified first idler.