Acceleration and/or tilt sensor having a ferromagnetic fluid that is located in a receptacle, and the receptacle constitutes a neutral position for the fluid, and the fluid is permanently magnetized, and a magnetic field detector arrangement is located at the receptacle to detect a displacement of the fluid, wherein a portion of the fluid can be displaced relative to the receptacle from the neutral position to an operating position by an external force while maintaining a continuous surface with the portion of the fluid remaining in the neutral position, and the fluid returns to the neutral position after removal of the external force.