To provide an apparatus for pretreatment for saccharification easily and continuously applying a treatment and capable of reusing ammonia at low cost. The apparatus has a mixing unit 2, a first heating unit 3, a separation unit 4, a transfer unit 6, an ammonia water supply unit 8 and an ammonia recovery unit 19. The apparatus may have the first heat exchanger 18, a second heat exchanger 25 and a heat supply unit 27 and further has a second heating unit 14. The apparatus may have a wet grinding unit 32 between the heating unit 3 and 25.