Provided is a microwave heating apparatus capable of effectively preventing the generation of sparks when an object containing a conductor (including a metal precursor such as a metal oxide) or a semiconductor is subjected to microwave heating. A microwave heating apparatus supplies a microwave so that the direction of the electrical flux line of the microwave is identical with the direction substantially parallel with a surface of a plate-like substrate and having thereon a pattern containing a conductor, a metal oxide, or a semiconductor, the substrate being arranged in the waveguide. The microwave heating apparatus also controls a pulse width of the microwave so that pulsed microwaves are supplied to the surface having the pattern thereon.