To provide a linear heating apparatus capable of being installed in a space-saving manner in various manufacturing lines, and efficiently heating a workpiece while applying suitable pressing force thereto.

A reflecting surface 10 including a partially elliptical shape is formed on an inner wall of a reflecting mirror 9. A slender infrared heater 8 is provided at one focal point surrounded by the reflecting surface 10. A slit-shaped opening 12 parallel to a longitudinal direction of the infrared heater 8 is formed on the long axis connecting two focal points. A transparent window 15 is fixed so as to cover the opening 12. An outer surface of the transparent window 15 substantially coincides with a second focal point, and the outer surface becomes a pressing surface for pressing an interconnector 3. The interconnector 3 is soldered in a state to be pressed against a solar cell 2, on the transparent window 15 by infrared rays condensed in a line shape.