A fuel tank for a straddle-type vehicle includes a two-piece structure made up of a lower panel and an upper panel, each panel having a flange which is formed at a side peripheral edge thereof and joined with the other flange to form the fuel tank, and side portions provided with tank side covers each having a specified vertical width to cover the flanges. The fuel tank is located in a manner such that the upper panel is exposed upward at an upper surface portion.