To provide a platform facility mounting structure facilitating work and simplifying construction to quickly return to an original state without needing to dig up a floor face of a platform in maintenance and replacement.

The mounting structure of a platform facility A installed not to project from the floor face of of a platform P of a station is constituted to fix the home facility A to a holding chassis 20 provided at the platform P. The holding chassis 20 is embedded in a mounting ditch 11 dug from the floor face of the platform P, and the home facility A is stored in the holding chassis 20 in a state of a unit U fixed to a support case 50, and fastened by fixing means 51.