Provided are a switch and an operation device which can expand the application range of switches using magnets, etc. A switch incorporated in an operation device includes a movable member with a first end side fixed and a second end side swinging when receiving a pressing, and a pressing member which presses the movable member, and further includes a permanent magnet (magnet) on the tip of the movable member, and a magnetic field detection part which detects a magnetic field. In response to an operation on the operation device, the pressing member of the switch presses the movable member downward. The magnetic field generated by the permanent magnet (magnet) and detected by the magnetic field detection part changes due to the pressing of the pressing member, and the switch outputs a signal based on the magnetic field detected by the magnetic field detection part.