An X-linked lift mechanism having first links (3) and second links (4) constituting an X-linked mechanism between a base frame (1) and a lift frame (2). A drive member (11) is pivotally rotatably installed between the other lateral side portions of the second links and is connected with boost arms (12) and a drive arm (13). Guide members (15) are provided for guiding the moving members (14) installed at the ends of the boost arms. The guide members are installed on the other lateral side portions of the first links in the length direction. Also, a linear actuator is provided so as to extend between the other lateral side of the first links and the drive arm.