Both conflicting functions of sealing and lubrication of sliding faces are made compatible over an entire period from the time of startup through the time of steady operation. A pair of sliding parts that relatively slide on each other is provided, one of the sliding parts being a stationary-side seal ring, the other of the sliding parts being a rotating-side seal ring, the seal rings each having a sliding face S formed radially for sealing sealed fluid from leaking, at least one of the sliding faces S being provided with fluid introduction grooves 10 configured to communicate with a first peripheral edge of the sliding face S and not to communicate with a second peripheral edge, and being provided with dynamic pressure generation grooves configured to communicate with the second peripheral edge of the sliding face S and not to communicate with the first peripheral edge.