Novel textile moisture sensors based on multi-layered braiding constructions offer attractive monitoring possibilities for many application fields of e-textiles (electronic textiles), especially for ambient air, which is the main focus of this work. In this paper the theoretical foundations and the production, as well as the procedural, mechanical and humidity tests on newly developed, textile-based sensors for moisture measurement are described. The sensor, which is based on a capacitive measurement principle, was tested in environments ranging from 22% to 94% relative humidity. Within this range, the electrical capacitance of the sensors changed up to 135% of the base capacitance, giving it a very high sensitivity.