The Uni-Directional Microwave Transmitter was created by jury-rigging a space communication ray. When fired, it will cause everyone within 20 meters of the blast to have their water molecules raised to their boiling point, which automatically kills them. However, anyone that's right next to the user when it's fired will not be harmed by it.
This weapon is found only in the last level; Caesar's Palace.
- The UMT is very effective against groups of powerful enemies, such as the Gunrilla. Instead of wasting a lot of ammo and health trying to fight them off normally, just take out the UMT and fire. It will kill them in one hit, saving the player a lot of trouble.
- It is also very effective against the hordes summoned by the Wolfinator, the final boss. This makes fighting him much easier.
- The UMT has very limited ammo, so the player should make sure they really need to use it before firing.
- The UMT's sprite is a slightly-modified XOP Flamethrower.
- The UMT works very similar to the Serious Bomb in other Serious Sam games. It's questionable to why they didn't make the UMT a Serious Bomb instead, however one thought is because it would require more animation to make him light the Serious Bomb to then be detonated, causing extra work to the creator.