The Sky Factory (referred to as the Flying Factory in the television series) is a steampunk vehicle that travels in the air that Romeo uses to get from place to place. It also has a control room to control the factory and the machines that it contains, such as its metal-sucking nozzle vacuum (referred as the Sucky Sucker), a mounted ray and expels gum clouds to pollute the environment. The Fly Bots take care of the factory for Romeo, while Robette serves as the co-pilot of the factory.
It first appeared in the Season 3 episode "Villain of the Sky" as the source of the expelled black and stinky gunk clouds in the air while it was being finished.
In "Protector of the Sky," Romeo used the factory to spread gunk clouds around the city and suck up everything using its metal-sucking nozzle machine. However, after a minor fight, the PJ Masks managed to stop Romeo by overriding the controls, causing the nozzle to suck up the gunk clouds and mess with the controls. Romeo and Robot tried to go after the team, but they ended up falling off the factory and into one of the gunk clouds, so they could not cause any trouble again that time.
In "PJ Sky Pirates," Romeo's Lab was being kept in the factory. It has yet to be determined if he will use the vehicle again in the future, although he likely will. This is proven to be true, as the lab was seen "Big Sister Motsuki."
In "PJ Robot Vs Romeo," the Sky Factory was losing pieces and Romeo and PJ Robot, despite not wanting to do it at first causing Robot to initiate psychiatrist mode, decided to work together while the PJs collect stray pieces.
In "Heroes of the Sky," the Sky Factory was used in an available plot to create multiple Sky Factories. Romeo used the power of several moon crystals and the PJ Crystal to build a ray that would, when at the edge of space, make more Sky Factories. However, after the PJ Masks and Luna Girl got back their crystals, the Sky Factories shrunk and fell.
In "Asteroid Accident," Romeo went after the PJ Masks in the Sky Factory in order to get the asteroid back, zapping them in the process. He also zapped the asteroid while the PJ Masks and Newton Star were on it. After Newton was able to surf the rock towards the factory and hit its ray, the invention zapped the factory, sending it spiraling back to Earth.
In "Robo-Wolf," Kevin was launched into the factory in order to get extra parts for the Wolfy Kids' homemade robot. He stole the new Robot Controller that Romeo invented for Robot and left with Robot in pursuit, but when the PJ Masks arrived to confront Romeo, he accused them of stealing the remote and used his new Truth Ray to make them confess, but to no avail. PJ Robot helped them escape afterwards.
In "Lost in Space," the factory was sent into space after Owlette accidentally launched a set of feathers at it from the PJ Air Jet. While Romeo made the repairs to return to Earth, he upgraded the computer to come up with a new plan. However, the computer, then named Mabel, took the place over afterwards, along with the Fly Bots, Robette, and the satellites. She was later defeated when the PJ Masks, Romeo, and Robot decided to work together.
The episodes "Glowy Moths" and "Take Romeo Off The Road" might have foreshadowed the creation of the Sky Factory because Romeo mentioned being "Villain of the Sky" several times and expressed his desire to rule the skies at the ends of the episodes.