To provide a heating electrode which can uniformly heat a material to be heated and having an irregular shape and can stably perform heating/holding-convey of the material to be heated by the heating electrode; and a method for heating food by using the heating electrode. [MEANS FOR SOLVING PROBLEMS] An assembly of pin electrodes (10) formed by conductive pins are slidably arranged in a through hole (21) of a pin support table (20). A pressure-variable gas chamber (30) whose pressure is variable is connected to the pin support table (20). By applying a plus pressure or a minus pressure to thegas chamber (30), the pin electrodes (10) are displaced relatively to the pin support table (20).