The invention relates to a flow plate (22, 32, 39a-39f) for a humidifier, and to such a humidifier having a plurality of flow plates (22, 32, 39a-39f) and water exchange membranes (15). Humidifiers of this kind are used in electrochemical systems, among other things. Conventional humidifiers have low performance because an exchange of moisture usually only takes place between the layers directly adjacent to the water exchange membranes. The flow plate (22, 32, 39a-39f) has a flow field with a plurality of free-standing support elements (27, 28, 29, 33, 34, 38, 40a-40d, 41, 43-52), wherein the support elements extend, at least in sections, perpendicular to the flat surface plane of the flow plate. Gas to be humidified or gas giving off moisture flows on the flow field. In the humidifier (1), the flow plates (22, 32, 39a-39f) are arranged in a stack, wherein a membrane composite (15, 16, 17) having at least one water exchange membrane (15) is arranged between each pair of adjacent flow plates in the stack. The support elements improve the performance of the humidifier and therefore the number of flow plates can be reduced, making a lower-weight and space-saving design possible.