When not in use, it is recommended that the microphone be stored in a cool, dry environment. It is best to keep the microphone in a plastic bag with some moisture absorbing crystals near the capsule. This will ensure any moisture that may be present around the mic, and especially the capsule, gets absorbed.
Regular checking on the microphone and the crystals is a good idea. If the crystals have changed colour this indicates they are saturated and can no longer absorb moisture from the air effectively. At this point they should be changed or dried out.
Correct storage of the microphone will ensure it will last a lifetime.