An operation device, comprising: an operation unit (10, 12, 13) configured to perform an input operation and to include a plurality of contact circuits including a plurality of fixed terminals discretely arranged and movable contacts each of which selectively changes a state between the fixed terminals to an ON state or an OFF state; a determination unit to which the contact circuits are connected and configured to determine that the operation unit (10, 12, 13) is in a state of ON operation or in a state of non-operation based on an ON state or an OFF state of each of the contact circuits; and an operation signal generation unit configured to output a signal indicating that the operation unit (10, 12, 13) is in a state of the ON operation based on a determination result of the determination unit, wherein, when the operation unit (10, 12, 13) is in a non-operation state, each movable contact is at an initial position where all of the plurality of contact circuits are in an OFF state, in response to an ON operation performed on the operation unit (10, 12, 13), the movable contacts move in conjunction with each other from the initial position to an end position where all of the plurality of contact circuits are turned on, and assuming that one of the plurality of contact circuits is a reference contact circuit and the others are output contact circuits (20B, 20C, 20D), the reference contact circuit is provided such that a distance from the initial position where the movable contact starts to move to a position where the reference contact circuit is turned on is smaller than that for the output contact circuits (20B, 20C, 20D). an operation unit (10, 12, 13) configured to perform an input operation and to include a plurality of contact circuits including a plurality of fixed terminals discretely arranged and movable contacts each of which selectively changes a state between the fixed terminals to an ON state or an OFF state; a determination unit to which the contact circuits are connected and configured to determine that the operation unit (10, 12, 13) is in a state of ON operation or in a state of non-operation based on an ON state or an OFF state of each of the contact circuits; and an operation signal generation unit configured to output a signal indicating that the operation unit (10, 12, 13) is in a state of the ON operation based on a determination result of the determination unit, wherein, when the operation unit (10, 12, 13) is in a non-operation state, each movable contact is at an initial position where all of the plurality of contact circuits are in an OFF state, in response to an ON operation performed on the operation unit (10, 12, 13), the movable contacts move in conjunction with each other from the initial position to an end position where all of the plurality of contact circuits are turned on, and assuming that one of the plurality of contact circuits is a reference contact circuit and the others are output contact circuits (20B, 20C, 20D), the reference contact circuit is provided such that a distance from the initial position where the movable contact starts to move to a position where the reference contact circuit is turned on is smaller than that for the output contact circuits (20B, 20C, 20D).