A hand grip mechanism includes a first member, a second member connected to the first member in a vertically moveable manner, a spring providing a biasing force to lower the second member with respect to the first member, and a hand grip configured by two grip links, each including a grip rotatably connected to the first member, a link rotatably connected to the second member below a connecting portion between the first member and the grip, and first and second connecting shafts each connecting the grip and the link below a connecting portion between the second member and the link. By a pressing operation to squeeze the hand grip against the biasing force of the spring, the grip and link in each grip link rotate relative to each other about the first connecting shaft during initial movement and about the second connecting shaft during final movement.