Abstract: The invention is concerned with a hollow-shaft encoder with motor-shaft protective cap, wherein the connection between the motor-shaft protective cap and hollow-shaft encoder is accomplished by means of repeatedly releasable and connectable frictional and/or form-fitting connection means via a relative movement between the motor-shaft protective cap and hollow-shaft encoder, and wherein the hollow-shaft encoder incorporates all electrical and mechanical components for the pick-up and output of the measuring signals and no electrical or mechanical components for the pick-up and output of the measuring signals are fixed on the motor-shaft protective cap. The hollow-shaft encoder with motor-shaft protective cap is more cost effective and simpler in its design, production, assembly, warehousing, maintenance and repair; as well as easier to manipulate.