A high-frequency heating device that includes: a first conductor; a second conductor disposed with the first conductor through a space therebetween; a high-frequency power source that is connected to the first conductor and the second conductor and that applies a high-frequency voltage between the first conductor and the second conductor; and a connection path that electrically connects the first conductor and the second conductor to each other at a first connection position and a second connection position. The first connection position is different from a first power feeding position at which the first conductor and the high-frequency power source are connected to each other on the first conductor, and the second connection position is different from a second power feeding position at which the second conductor and the high-frequency power source are connected to each other on the second conductor.