[Problem] To provide a trailer house the roof of which can be effectively used as a rooftop deck, which trailer house has improved habitability, and which trailer house can satisfy a user's taste to a high level. [Solution] This trailer house is provided with: a dwelling structure provided with a wall body and a roof body positioned on the wall body and fixed to the wall body; and a support structure provided with wheels and a frame body integrated with the dwelling structure. The trailer house is towed to a destination by an automobile, and fixed at the destination to be used, and is characterized in that the roof body is provided with: a planar rooftop deck utilized part; a surrounding part that is positioned outward the peripheral edge of the rooftop deck utilized part; and an entrance for entering or exiting the rooftop deck utilized part from/to the inside of the dwelling structure.