To provide sufficient strength even without a center tunnel and to provide sufficient receiving capacity for a running car function part in a range centering around the running car, in the floor structure of a passenger car extending at least throughout the whole bottom of a passenger room and having a plurality of function ranges.

A single part type plate-form central part 2 is reinforced and incorporated in the central function range of a floor structure, and receiving parts 6, 7, and 8 for a plurality of running car function parts, i.e., a console 8 for the operation lever of a manual brake, a holder 6 for a gear case, and a receiving part 7 for the sensor of an air bag device are integrally arranged at the central part 2. At least three pot-form mounting tools 6, to which the gear cases are attached with a distance therebetween, are arranged as a receiving part for the gear case. The pot-form mounting tools 6 are protruded in an up state from the bottom plate of the central part 2 by a distant enough to allow laying of at least one cable passage below the gear case between the pot-form mounting tools 6.