A crane comprising: a telescopic boom including an inner boom element (141, 142) and an outer boom element (142, 143) that overlap each other to be extendable and contractible; a telescoping actuator that is a telescoping cylinder including a fixed side member and a movable side member that is configured to be movable with respect to the fixed side member, and displaces one boom element of the inner boom element (141, 142) and the outer boom element (142, 143) in a telescoping direction; a first coupling member (454a, 454b) that releasably couples the movable side member to the one boom element; a second coupling member (144a, 144b) that releasably couples the inner boom element (141, 142) and the outer boom element (142, 143); an electric drive source provided in the movable member; a first coupling mechanism that displaces the first coupling member (454a, 454b) by using power of the electric drive source, to cause the movable side member and the one boom element to switch between a coupled state and a non-coupled state; a second coupling mechanism displaces the second coupling member (144a, 144b) by using the power of the electric drive source, to cause the inner boom element (141, 142) and the outer boom element (142, 143) to switch between the coupled state and the uncoupled state; and a position information detection device (44, 500A, 500B, 500C, 500D, 500E, 500F, 500G, 500H) that detects information relating a position of the first coupling member (454a, 454b) and the second coupling member (144a, 144b) based on an output of the electric drive source, characterized in that the crane further comprises a switch gear (450, 460) that selectively transmits the power of the electric drive source to any one coupling mechanism of the first coupling mechanism and the second coupling mechanism. a telescopic boom including an inner boom element (141, 142) and an outer boom element (142, 143) that overlap each other to be extendable and contractible; a telescoping actuator that is a telescoping cylinder including a fixed side member and a movable side member that is configured to be movable with respect to the fixed side member, and displaces one boom element of the inner boom element (141, 142) and the outer boom element (142, 143) in a telescoping direction; a first coupling member (454a, 454b) that releasably couples the movable side member to the one boom element; a second coupling member (144a, 144b) that releasably couples the inner boom element (141, 142) and the outer boom element (142, 143); an electric drive source provided in the movable member; a first coupling mechanism that displaces the first coupling member (454a, 454b) by using power of the electric drive source, to cause the movable side member and the one boom element to switch between a coupled state and a non-coupled state; a second coupling mechanism displaces the second coupling member (144a, 144b) by using the power of the electric drive source, to cause the inner boom element (141, 142) and the outer boom element (142, 143) to switch between the coupled state and the uncoupled state; and a position information detection device (44, 500A, 500B, 500C, 500D, 500E, 500F, 500G, 500H) that detects information relating a position of the first coupling member (454a, 454b) and the second coupling member (144a, 144b) based on an output of the electric drive source, characterized in that the crane further comprises a switch gear (450, 460) that selectively transmits the power of the electric drive source to any one coupling mechanism of the first coupling mechanism and the second coupling mechanism.