An induction heater and a water dispenser having an induction heater are provided. The induction heater may include a hot water tank assembly formed by coupling edges of a first cover and a second cover to each other and provided with an inner space to heat liquid. The first cover may be configured to have a flat plate shape and to be heated by a working coil. The second cover may include a base configured to face the first cover and separated from the first cover, and a welding portion formed by welding with the first cover and provided on a protruding surface that protrudes from the base toward the first cover.