PURPOSE: To realize a small-sized thin electrolytic cell by setting a first case having a cup shape and having a raw water supply passage provided to the side surface thereof and a first emitting passage provided to the bottom surface thereof and a second case having a second emitting passage provided to the bottom surface thereof in opposed relationship to cover a laminate and holding the laminate between the bottom surfaces of the first and second cases.

CONSTITUTION: A water permeable second plate-shaped electrode 30 having an outer shape almost same to that of a first plate-shaped electrode 29 and a second C-shaped spacer 25 having an outer shape almost same to that of a first C-shaped spacer 24 are successively laminated so that the outer shapes on the one half sides of them arranged to form a laminate. This laminate is covered by mutually opposing a first case 34 having a cup shape and having a raw water supply passage 33 provided to the side surface thereof and a first emitting passage 31 provided to the bottom surface thereof and a second case 35 having a second emitting passage 32 provided to the bottom surface thereof and held between the bottom surfaces of the first and second cases 34, 35. By this constitution, a small-sized and extremely thin electrolytic cell can be realized.