There is provided a valve device for a fuel tank including: a housing; a first float valve accommodated in a first valve chamber; and a second float valve accommodated in a second valve chamber. The housing includes a housing body and a lower cap. The housing body has a housing body peripheral wall. The housing body peripheral wall has a first valve chamber forming wall that forms an outer periphery of the first valve chamber, and a second valve chamber forming wall that has a contour shape different from that of the first valve chamber forming wall and that forms an outer periphery of the second valve chamber. The lower cap has a cap peripheral wall having a shape fitting to the housing body peripheral wall.