To provide a floor surface structure of a parking garage enabling a car to enter the parking garage easily without impairing an external appearance of the parking garage.

This floor surface structure of the parking garage is constituted by providing guide grooves 8, 8 engaging with side parts of wheels of the car 4 entering the parking garage to guide the car on a floor surface of the parking garage 3, providing a floor finish material 6a provided with a cushion material 6b on its lower face side in each of the guide grooves 8, 8 to make its upper face part flush with adjacent floor surface, and making the cushion materials 6b to be compressed and deformed in the vertical direction when the wheels ride on the finish materials 6b while the car 4 enters the parking garage 3, thereby letting the guide grooves 8 appear. Then, the wheels are guided into the guide grooves 8, 8, and the car 4 is guided to a parking position. When the car 4 leaves the parking garage 3, the cushion materials 6b are restored, and its upper face part returns to a position of height being flush with adjacent floor surface.