An induction coil is formed by winding an electrically conductive wire around an iron core, and at least one turn of a pipe of electrically conductive material is wound around the induction coil. The pipe is short-circuited at positions other than where the pipe is wound around the induction coil. An A.C. power source is connected to the induction and preheated fluid is supplied to the pipe to be further heated by induction within the pipe. Since the pipe has a large heat transfer area, efficient heat exchange can be obtained. This heating system is connected to a steam generator, which supplies the preheated fluid to it. The steam generator includes an induction coil of an electrically conductive wire wound on an iron core and a metal material forming a plate disposed on the iron core. The bottom surface of the metal material provides a magnetic flux path for the induction coil. An A.C. power source is connected to the induction coil to induce induction heating in the plate and thus to vaporize water or other fluid supplied to the steam generator into a space within the steam generator above the plate. The steam generator also includes a gas-liquid separator above the plate for separating steam from condensed droplets.