The Fenton Thermos is a thermos used to capture ghosts, and also half-ghosts, such as in "Secret Weapons" when Danny was accidentally sucked into the Fenton Thermos. After capturing a ghost in the thermos, Danny releases the ghost back into the Ghost Zone, through the Ghost Portal. The device can hold multiple ghosts at a time; if damaged, the ghosts within are all set free. Another thing to note is that the thermos can capture any ghost, regardless of size, shape or form. Danny has been able to snare huge ghosts such as a super-powered Desiree and a reality-warped Freakshow. In "Mystery Meat," it turns out that the Fenton Thermos needed to be charged with ectoplasmic energy in order for it to work. However, it doesn't work on humans or any non-ghost life-forms. The thermos isn't a surefire containment unit if some ghosts are so powerful that they can resist and even break free from containment: Dark Danny was seen slowly escaping of the one he was trapped in his last appearance, and the ghost-version Freakshow destroyed his thermos before being turned back to normal. It should be noted that because the thermos is only used bring ghosts back to the Ghost Zone, its use is redundant when already there. As such, Danny is never seen using it in the Ghost Zone which makes his trips there much harder, though he did use it to seal up the portal Wulf tore open when it was set to reverse polarity.
- The Fenton Thermos is based off the ghost trap from the 1984 film, Ghostbusters, and its sequel, Ghostbusters II.
- The Fenton Thermos is similar to the Poltergust 3000 from the 2001 Nintendo GameCube video game, Luigi's Mansion and later the Poltergust 5000 from Luigi's Mansion Dark Moon as it sucks up ghosts, too. Another similar object is the Fenton Ghost Weasel, which is also ghost-sucking vacuum.
- Valerie has a similar thermos in the red in black style found in her arsenal.
- It has a loop on its lid to attach it to the middle so you wont lose it, however nobody uses it.