[ZilverZilvia]

It might be a dead battery. It clicks because there isn't enough current to the starter solenoid/motor. OR, if you know the battery is perfect, your deduction is perfect, and it's either the starter solenoid, or starter motor itself.
Check your battery voltage first. It could also be your alternator (not recharging your battery, supplying enough current to the rest of your car while running, draining the battery more...)