The present invention relates to a detachable roller means and a movable bag or case having said detachable roller means, said roller means comprises a roller seat (1) and a roller assembly, which are detachably connected to each other. The roller seat has a penetration opening (1-1) and a guide in which a spring-pretensioned button plate (2-10) is guided. Said button plate has a button arm (2-3), by means of which the button plate is displaceable along the guide. The roller assembly has a roller holder and a roller (3). The roller holder is provided on its upper side with a lug boss (2-5) and a shaft (2-8) projecting from the lug boss. The shaft is provided with an upper stop (2-9). In a mounting status, the lug boss is abutted against the bottom of the roller seat tightly and, viewed in the insertion direction of the shaft, the button plate is engaged behind the upper stop in a spring-pretensioned manner. The button plate can be brought out of engagement with the upper stop in opposite to the spring pretension. The roller means according to the present invention is not only permanently firm, but also can be mounted and detached easily.