To provide a falling film evaporator in which the area required for installing equipment (installing space) can be reduced and the installation cost can be lowered.

Splash-entrained steam generated from a first effect falling film heating boiler 1 is introduced into an outer peripheral part of a second effect falling film heating boiler 4. In this peripheral part, a splash separator 3 having a jacket contraction for separating a splash in the steam by centrifugal force generated by turning the entrained steam in the outer peripheral part of the second effect falling film heating boiler 4 is arranged and also in a part covered with the splash separator 3 of the outer peripheral part of the second effect falling film heating boiler 4, a steam introducing port 5 for introducing the steam from which the splash is separated is arranged. After the entrained steam generated from the first effect falling film heating boiler 1 is introduced into the splash separator 3 arranged in the outer peripheral part of the second effect falling film heating boiler 4 to separate the splash in the steam, the steam from which the splash is separated is introduced into the second effect falling film heating boiler 4.