To provide a novel and improved water recovery method capable of improving the water recovery ratio.

A problem-solving water recovery method reflecting a certain standpoint of the present invention includes a step of streaming, into serial flow channels obtained by serially linking multiple low-concentration-side flow channels, a low-concentration solution including water and a step of streaming, into high-concentration-side flow channels obtained by linking, via semi-permeable membranes, the respective members of the multiple low-concentration-side flow channels, a high-concentration solution having an identical concentration. It becomes possible, from this standpoint, to maintain, at high values, osmotic pressure differences within the respective forward osmosis (FO) membrane modules, above all the osmotic pressure difference within the latter-step FO membrane module.