Abstract: A vessel for use with a high-frequency induction heater, having a bottom wall adapted to be heated by the induction heater for heating fluid contents of the vessel. At least the bottom wall is made from a cladding composite which consists of an aluminum alloy layer and a stainless steel layer clad with each other under pressure. The aluminum alloy layer is disposed on the inner side of the vessel, and consists of not more than 0.30 wt % of Si, not more than 0.7 wt % of iron, not more than 0.25 wt % of copper, 1.0-1.5 wt % of manganese, 0.8-1.3 wt % of magnesium, not more than 0.25 wt % of zinc, and the balance being aluminum.