A raw tire preheating device comprises tread section preheating mechanism (16) consisting of a front coil (21) disposed in opposed relation to a tread section (4a) for producing a high frequency magnetic field and applying it to the tread section (4a), and of a core mechanism having center cores (24), separation cores (25) and side cores (26) that are made of a material containing a ferromagnetic low electric conductivity material for pulling in the high frequency magnetic field and that set the high frequency magnetic filed in such a distribution as to uniformly preheat the whole of the tire widthwise area of the tread section (4a), and a mechanism for moving at least either the tread section preheating mechanism (16) or the raw tire (4).
