A plug-in heater for hot curlers is constituted in the following manner: because the power plug can be positioned at the storage location, it is constituted to possess a compact size; in particular, because the power plug can be positioned at the protruding positions in two perpendicular directions (a rear-side protruding direction and a lower-side protruding direction), the range for inserting the power plug can be expanded even when the electrical outlet is located at different locations at the housing facilities. Plug-storing groove 15 is formed extending from upper surface (10) to lower surface (13) of the main body case, the base of power plug 2 is rotatably supported at a lower position within plug-storing groove 15 above, power plug 2 is formed so as to be positioned around the rotatably-supporting point at an upward storing position P1, at a rear-side protruding position P2, and at a lower-side protruding position P3, and locking means 3 and 4 are formed for positioning and fixating the power plug at these positions.