To provide a front structure of a cab, which can set a resonance frequency of a dash panel to a desired resonance frequency reducing noise caused by the vibration of the dash panel, by increasing the support rigidity of the dash panel.

The front structure of a cab includes: a floor panel 13 extended from a front end lower part of the cab 3 to a rear side and demarcating the bottom part of a cabin 10; the dash panel 15 rising from a front end of the floor panel 13 along the vehicle width direction and demarcating a front part of the cabin 10; and an installation bar 50. The installation bar 50 has: an installation bar body 51 supporting an instrument panel from the front side at an upper part of the floor panel 13; and a support post 52 connecting the installation bar body 51 to the floor panel 13 behind the dash panel 15 and supporting the installation bar body 51 from a lower side; wherein a lower rib 60 extended to the rear face lower part of the dash panel 15 and joined to the rear face lower part is formed at the front side lower part of the support post 52.