The invention provides a heating apparatus which has a high heating efficiency, can locally heat a part to be heated, can achieve a rated temperature for an extremely short time after starting the heating, reduces a large rush current and flicker at a time of lighting, has a long service life, and can correspond to a plurality of modes having different heating widths, an infrared ray lamp suitable for the heating apparatus, and a high reliable electronic apparatus having the above-mentioned heating apparatus. The infrared ray lamp in accordance with the invention seals one or a plurality of heat generating elements in a glass tube, the heat generating elements having a shape extending in a longitudinal direction at a fixed width and an opening part extending substantially in a longitudinal direction provided only in a part in the longitudinal direction.