Portable transmitter having space for containing mechanical key

A portable transmitter for transmitting signals to a device to be operated, the portable transmitter having a case, electronic components and a battery for supplying power to the electronic components, the electronic components and the battery being contained in the case, the case comprising:

• a key space for containing a mechanical key therein;
• a key hook for keeping the mechanical key in position in the key space;
• a releasing lever for releasing the key hook to take out the mechanical key from the key space;
• an opening for loading and unloading the battery;
• a battery cover closing the opening, the battery cover being fixed to the case with screws;
• a seal member disposed between the battery cover and the case to be compressed therebetween to thereby seal the opening;
• a sliding cover covering the battery cover and the screws, the sliding cover being slidably removable from the case;
• and
• a cover hook for locking the sliding cover in its closing position, wherein:
• the cover hook is simultaneously released when the key hook is released by operating the releasing lever.