The present disclosure aims to provide a high-durability switch device. The switch device includes: a switch key top and a switch key bottom that are freely displaceable relative to each other, the switch key top including key top reception and transmitting coils that are connected to each other, and the switch key bottom including: a key bottom transmitting coil having a relative positional relationship with the key top receiving coil that changes according to a relative displacement operation with respect to the switch key top; a key bottom receiving coil having a relative positional relationship with the key top transmitting coil that changes according to the relative displacement operation with respect to the switch key top; a current supplier supplying current to the key bottom transmitting coil; and a determiner determining relative displacement with respect to the switch key top from induced current in the key bottom receiving coil.