To provide a friction clutch and a driving force transmission device capable of being inexpensively manufactured without degrading workability.

The friction clutch 34 comprises two inner clutch plates 34a and one outer clutch plate 34b having sliding faces S1, S2, respectively, to be in mutual contact. Known special gas nitrocarburizing treatment is given to the sliding faces S1 of the inner clutch plates 34a. On the sliding face S1, a plurality of fine width grooves 40 are provided in parallel along the peripheral direction by cutting work. On the other hand, a DLC film 42 is applied to the sliding face S2 of the outer clutch plate 34b.