To provide a noise filter for high-frequency generators which serves to attenuate the leaked noises of a specific bandwidth from a high-frequency generator.

The noise filter for high-frequency generators includes many choke coils in each of which a first core type inductor, an air-core inductor, and a second core type inductor are connected in series with each other. A high-frequency-energy absorbing member is inserted into each of the first and second core type inductors, and no high-frequency-energy absorbing member is inserted into the air-core inductor. The high-frequency-energy absorbing member is made of either one kind of iron oxide, tin alloy, and ferrite, and has its sectional area for attenuating the noises in the bandwidth of 400-900 MHz.