A modular computer keyboard assembly that separates keyboard components into two groups. One group of components becomes a detachable module, while the other group stays as the base module. Depending on applications, the detachable module can be further broken into more sub-modules. Keyboards manufactured following the method proposed by present invention are modular in nature, and are conducive to reducing the costs for keyboard services and exchanges, costs for curing future environmental hazards and costs for fitting suitable user keycaps for swapping among different languages and computer applications.