A clutch device that switches transmission and cutoff of rotational force between two rotating shafts, the clutch device comprising: a first rotating shaft in which a plurality of groove portions are formed to be spaced apart from each other in an inner or outer circumference and in a circumferential direction; a second rotating shaft that is arranged coaxially with the first rotating shaft and arranged such that at least part of the second rotating shaft overlaps the first rotating shaft; a plurality of engaging parts that are provided on the second rotating shaft so as to be capable of moving in a radial direction of the second rotating shaft and arranged to be spaced apart from each other in a circumferential direction of the second rotating shaft; and an advancing/retracting mechanism that causes the engaging part to advance and retract in a direction toward the groove portion, characterised in that the plurality of engaging parts have: a first engaging part that enters any one first groove portion of the plurality of groove portions, when the plurality of engaging parts are moved toward the plurality of groove portions by the advancing/retracting mechanism, irrespective of a rotational phase difference between the first rotating shaft and the second rotating shaft; and a second engaging part that enters a second groove portion different from the first groove portion, when the first engaging part moves in one rotational direction of the clockwise and counter-clockwise directions in a state of entering the first groove portion and engages one of the two side surfaces of the first groove portion, the one side surface being located on the one rotational direction side, and wherein the second engaging part is configured such that: when entering the second groove portion, the second engaging part engages one of the two side surfaces of the second groove portion, the one side surface being located on the other rotational direction side. a first rotating shaft in which a plurality of groove portions are formed to be spaced apart from each other in an inner or outer circumference and in a circumferential direction; a second rotating shaft that is arranged coaxially with the first rotating shaft and arranged such that at least part of the second rotating shaft overlaps the first rotating shaft; a plurality of engaging parts that are provided on the second rotating shaft so as to be capable of moving in a radial direction of the second rotating shaft and arranged to be spaced apart from each other in a circumferential direction of the second rotating shaft; and an advancing/retracting mechanism that causes the engaging part to advance and retract in a direction toward the groove portion, characterised in that the plurality of engaging parts have: a first engaging part that enters any one first groove portion of the plurality of groove portions, when the plurality of engaging parts are moved toward the plurality of groove portions by the advancing/retracting mechanism, irrespective of a rotational phase difference between the first rotating shaft and the second rotating shaft; and a second engaging part that enters a second groove portion different from the first groove portion, when the first engaging part moves in one rotational direction of the clockwise and counter-clockwise directions in a state of entering the first groove portion and engages one of the two side surfaces of the first groove portion, the one side surface being located on the one rotational direction side, and wherein the second engaging part is configured such that: when entering the second groove portion, the second engaging part engages one of the two side surfaces of the second groove portion, the one side surface being located on the other rotational direction side.