To provide a passenger step device of a construction machine capable of avoiding interference with a lower frame without attaching/detaching a step during the retraction, and omitting separate transport of the step from a machine body.

Lower side frames 11L, 11R are retractably provided on the outer side of a lower frame 10 in the vehicle width direction. A step 20 is fixed to the lower side frames 11L, 11R selectively to the upper mounting position or the lower mounting position. When the step 20 is fixed to the lower mounting position, the step is arranged so as not to be protruded upward from the lower side frames 11L, 11R.