ObjectIn a cab frame structure for a construction machine in which a front pillar and a roof pillar are configured by one tubular material, the cab frame structure for the construction machine in which an attachment position of a front header can be reversibly raised and an upward viewing angle of a driver is enlarged is provided.Solving MeansA front pillar 1 and a roof pillar 2, which constitute a cab frame of the construction machine, are configured by one tubular material 9 having a curved portion 10 at a joint between them, and by making a curvature radius of a curve outer side 10a in the curved portion 10 smaller than a curvature radius of a curve inner side 10b, a space 12 to raise an accommodation position of a top end 7x of a front window unit 7 is formed in the curved portion 10. A front header 4 is arranged at the position of the top end 7x of the front window unit 7 accommodated in the space 12. With this configuration, the attachment of the front header 4 can be reversibly raised, and an upward viewing angle θ2 of a driver can be expanded.