A lock device for locking a seat of a vehicle relative to a striker fixed to a vehicle body, comprising: a base plate having a striker receiving recess for receiving therein the striker; a latch plate rotatably connected to the base plate and having a striker catching recess for catching the striker, the latch plate being rotatable between a latch position to cause the striker catching recess to catch the striker and an unlatch position to cause the striker catching recess to release the striker; a lock plate rotatably connected to the base plate and rotatable between a lock position to cause the latch plate to be locked at the latch position and an unlock position to cause the latch plate to be unlocked; and a cover member having a U-shaped flange formed thereon, the cover member covering one major surface of the base plate having the U-shaped flange neatly disposed on a peripheral edge of the striker receiving recess, in which the latch plate comprises: a latch plate proper including upper and lower finger portions (3d, 3h) between which the striker catching recess is defined, an upper surface of the lower finger portion including a depressed main portion located near the bottom of the striker catching recess, a raised leading end portion and a stepped portion provided between the depressed main portion and the raised leading end portion; and characterized by the latch plate further comprising a film that covers the latch plate proper except the raised leading end portion, the film covering the depressed main portion of the upper surface in such a manner that an outer surface of the film is flush with the stepped portion, the film covering the depressed main portion being deformable when pressed by the striker. a base plate having a striker receiving recess for receiving therein the striker; a latch plate rotatably connected to the base plate and having a striker catching recess for catching the striker, the latch plate being rotatable between a latch position to cause the striker catching recess to catch the striker and an unlatch position to cause the striker catching recess to release the striker; a lock plate rotatably connected to the base plate and rotatable between a lock position to cause the latch plate to be locked at the latch position and an unlock position to cause the latch plate to be unlocked; and a cover member having a U-shaped flange formed thereon, the cover member covering one major surface of the base plate having the U-shaped flange neatly disposed on a peripheral edge of the striker receiving recess, in which the latch plate comprises: a latch plate proper including upper and lower finger portions (3d, 3h) between which the striker catching recess is defined, an upper surface of the lower finger portion including a depressed main portion located near the bottom of the striker catching recess, a raised leading end portion and a stepped portion provided between the depressed main portion and the raised leading end portion; and characterized by the latch plate further comprising a film that covers the latch plate proper except the raised leading end portion, the film covering the depressed main portion of the upper surface in such a manner that an outer surface of the film is flush with the stepped portion, the film covering the depressed main portion being deformable when pressed by the striker. a latch plate proper including upper and lower finger portions (3d, 3h) between which the striker catching recess is defined, an upper surface of the lower finger portion including a depressed main portion located near the bottom of the striker catching recess, a raised leading end portion and a stepped portion provided between the depressed main portion and the raised leading end portion; and characterized by the latch plate further comprising a film that covers the latch plate proper except the raised leading end portion, the film covering the depressed main portion of the upper surface in such a manner that an outer surface of the film is flush with the stepped portion, the film covering the depressed main portion being deformable when pressed by the striker.