A crane, comprising: a machine body; a boom rotatably mounted on the machine body and having a structure which allows the length of the boom to be changed; and a derricking mechanism configured to rotate the boom to raise and lower the boom with respect to the machine body, wherein: the derricking mechanism includes a guy line, a linking device provided on a distal end of the boom to connect one end of the guy line to the distal end of the boom, and a guy line operating device configured to draw the guy line rearward to raise the boom and configured to advance the guy line to lower the boom; the distal end of the boom has a back surface which faces rearward when the boom is in a vertical position, and a ventral surface which faces forward when the boom is in the vertical position; the linking device includes a joint connected to one end of the guy line, and a support device provided on the distal end to support the joint so as to locate the joint at a position away from the back surface and opposite to the ventral surface; and the support device includes a holding member which holds the joint, the holding member allowing the position of the joint to be selectively changed to a plurality of different positions in a first direction perpendicularly intersecting an axis of the boom and a rotary axis of the boom, wherein the holding member includes a plurality of holding parts respectively disposed at the different positions in the first direction, each of the holding parts being configured to detachably hold the joint, characterized in that the support device includes a supporting member which is disposed between the holding member and the back surface of the distal end, and the supporting member is coupled with the joint held by the holding member to support the holding member at the position of the joint via the joint. a machine body; a boom rotatably mounted on the machine body and having a structure which allows the length of the boom to be changed; and a derricking mechanism configured to rotate the boom to raise and lower the boom with respect to the machine body, wherein: the derricking mechanism includes a guy line, a linking device provided on a distal end of the boom to connect one end of the guy line to the distal end of the boom, and a guy line operating device configured to draw the guy line rearward to raise the boom and configured to advance the guy line to lower the boom; the distal end of the boom has a back surface which faces rearward when the boom is in a vertical position, and a ventral surface which faces forward when the boom is in the vertical position; the linking device includes a joint connected to one end of the guy line, and a support device provided on the distal end to support the joint so as to locate the joint at a position away from the back surface and opposite to the ventral surface; and the derricking mechanism includes a guy line, a linking device provided on a distal end of the boom to connect one end of the guy line to the distal end of the boom, and a guy line operating device configured to draw the guy line rearward to raise the boom and configured to advance the guy line to lower the boom; a guy line, a linking device provided on a distal end of the boom to connect one end of the guy line to the distal end of the boom, and a guy line operating device configured to draw the guy line rearward to raise the boom and configured to advance the guy line to lower the boom; the distal end of the boom has a back surface which faces rearward when the boom is in a vertical position, and a ventral surface which faces forward when the boom is in the vertical position; the linking device includes a joint connected to one end of the guy line, and a support device provided on the distal end to support the joint so as to locate the joint at a position away from the back surface and opposite to the ventral surface; and a joint connected to one end of the guy line, and a support device provided on the distal end to support the joint so as to locate the joint at a position away from the back surface and opposite to the ventral surface; and the support device includes a holding member which holds the joint, the holding member allowing the position of the joint to be selectively changed to a plurality of different positions in a first direction perpendicularly intersecting an axis of the boom and a rotary axis of the boom, wherein the holding member includes a plurality of holding parts respectively disposed at the different positions in the first direction, each of the holding parts being configured to detachably hold the joint, characterized in that the support device includes a supporting member which is disposed between the holding member and the back surface of the distal end, and the supporting member is coupled with the joint held by the holding member to support the holding member at the position of the joint via the joint.