WORK MACHINE

A working machine (1) includes an operator's seat (6), a seat base (83) supporting the operator's seat (6), and a slide rail (84L, 84R) for adjustment of a position of the operator's seat (6), the slide rail (84L, 84R) being located between the seat base (83) and the operator's seat (6), in which the seat base (83) includes a rail mount (718) for attachment of the slide rail (84L, 84R), the rail mount (718) having a downward convex curve (D1) which is curved to deviate from the slide rail (84L, 84R) with increasing distance from each of opposite ends of the rail mount (718) in a longitudinal direction of the slide rail (84L, 84R) and with decreasing distance to a center of the rail mount (718) in the longitudinal direction.