Fixing a membrane to a cassette for an electrolysis cell

A membrane assembly for an electrolyser cassette (1) is provided. The membrane assembly comprises a membrane (4) and a spacer arrangement comprising a first spacer portion (13) and a second spacer portion (14). The membrane (4) is arranged between the first gasket part (13) and the second gasket part (14), and the gasket arrangement comprises locking means (15, 16) for fixing the first gasket part (13), the membrane (4) and the second gasket part (14) relative to each other. The invention further relates to an electrolyser box (1) comprising such a membrane module and to a method for assembling such a membrane module.