PROBLEM TO BE SOLVED: To ensure strength around a driver seat, a front visual field, and an indoor space around a driver.SOLUTION: A cabin comprises a cabin frame 6 that comprises: left and right front posts 8 left and right rear posts 9 a front beam material 16 for connecting upper end sides of the left and right front posts 8 a rear beam material 17 side beam materials 18 a rear lower part connection material 19 a front lower part connection material 25 a front lower part frame body 24 a side frame material 21 which extends forward from the lower end part of each of the left and right rear posts 9, and is shifted downward and a side lower part connection material 23. A rear panel 14 for blocking between the left and right rear posts 9 and a door panel 15 for blocking between the rear post 9 and the front post 8 are provided, and the left and right side beam materials 18 and the side frame material 21 are arranged so as to spread outward in a left and right direction from the rear end to the front end.
