A filter device that suppresses electromagnetic interference generated in an alternating current circuit connected to a power converter with an alternating current output includes: a common mode choke connected to between any one terminal at an input side, an output side, or a direct current link of the power converter and input terminals of the alternating current circuit; and a connecting element that connects an outgoing line from a neutral point of the alternating current circuit to a reference potential point having little potential variation at an upstream of the common mode choke.