A cab frame (14) is supported on brackets (12, 13) provided at a plurality of positions of a vehicle body frame (11) with dampers (15). Movement limiting mechanisms (30) for limiting a movement at least in a vertical direction of the cab frame (14) are provided between the brackets (12, 13) and the cab frame (14). Further, the movement limiting mechanisms (30) are provided at least at two positions. Each movement limiting mechanism (30) includes a lower limiting portion (31) arranged close to the brackets (12, 13) and constituted by a plate member, and an upper limiting portion (32) arranged close to the cab frame (14) and constituted by a plate member in the same manner. The lower limiting portion (31) is integrally structured with the brackets (12, 13). Recesses (33, 34) are formed in a side edge of at least one of the lower limiting portion (31) and the upper limiting portion (32), and the limiting portion in the other limiting portion is positioned within the recesses (33, 34). Accordingly, in the cab supporting apparatus of a work machine, the movement limiting mechanism (30) is arranged by using the brackets (12, 13) for supporting the cab frame (14). Therefore, it is possible to simplify the structure of the cab supporting apparatus by reducing the number of the parts, and it is possible to make the structure compact. Accordingly, even in a compact work machine, the cab supporting apparatus is easily mounted.