A fuel tank includes a first fuel chamber for receiving liquid fuel; a communication chamber communicated with the first fuel chamber and having a bottom higher than a bottom of the first fuel chamber; and a second fuel chamber communicated with the communication chamber, the second fuel chamber having a bottom lower than the bottom of the communication chamber. The fuel tank also includes a sleeve member having a lower end opening toward the bottom of the communication chamber, and configured so that fuel evaporative emissions are discharged while liquid fuel is supplied to the first fuel chamber. The first fuel chamber, the communication chamber, and the second fuel chamber are all molded integrally by resin blow molding. The communication chamber is provided with a protrusion which is convex when viewed from inside the communication chamber, and a depression which is concave when viewed from outside of the communication chamber.