To provide a ship capable of reducing the gross weight of the ship body to the minimum and a method of carrying in/out of a main engine of the ship.

The ship has the main engine 1 for generating the driving force on the water, an engine room 2 where the main engine 1 is stored, a car deck 3 extending in the cross direction above the engine room 2 with a loading door 3a above the engine room 2, and a ceiling 5 covering the car deck 3, and also has a hole 5a on the ceiling 5 just above the main engine 1 for inserting a wire of a crane. Since the wire is inserted into the hole from outside to lift the main engine, it is not necessary to mount a carry means of the main engine in the ship itself, so that the total weight of the ship body can be reduced.