FUEL TANK

A fuel tank having an integrated component, wherein: the integrated component is equipped with a carrier part (11A) which is a rigid body having a plurality of engaging parts (15A), and also equipped with a plurality of struts (12A) which have engageable parts (30A) to be engaged by the plurality of engaging parts (15A); the engageable parts (30A) of the struts (12A) have an upper contact surface and a lower contact surface which are formed so as to be separated from one another in the height direction; and the engaging parts (15A) of the carrier part (11A) have a biasing part (114) which enters the space between the upper and lower contact surfaces when engaging the struts (12A), and produces a biasing force in the direction in which the upper and lower contact surfaces are separated from one another.