Modularized water separating membranes in a plural number of units are provided. A membrane container used in a dehydration system for separating water from treated fluid includes a shell part 11 having a permeated fluid outlet nozzle 16 and containing a plurality of water separating membranes arranged in parallel with respect to the flow direction of treated fluid; an upper channel part 12 having a treated fluid inlet nozzle 14 and connecting with the upper end of the shell part 11; and a lower channel part 13 having a treated fluid outlet nozzle 15 and connecting with the lower end of the shell part 11.
