The portable electronic apparatus has a box-like casing having a peripheral wall, and a pack receptacle defined within the casing. The pack receptacle has an opening portion opened in the peripheral wall. A packaged functional component is stored in the pack receptacle, such that the functional component can be detached therefrom through the opening portion. The pack receptacle of the casing is provided with a locking member for holding the functional component. The locking member is movable by manual operation between a locked position where the locking member is hooked on the functional component and a lock-released position where the locking member leaves the functional component. The pack receptacle is provided with a spring for energizing the functional component in the direction in which the functional component is pushed out through the opening portion. The opening portion of the casing and the locking member are covered with a detachable cover.