A thrust washer, comprising a ring-shaped member made of a material containing a resin, the ring-shaped member having a front surface and a back surface, wherein at least one of the front surface or the back surface of the ring-shaped member slides against another member, wherein at least one of the front surface or the back surface has four or more oil grooves, each being a flow path for lubricating oil, wherein an oil groove carrying surface is a surface to slide against another member, wherein the oil grooves each have a longitudinal direction that forms an angle falling within a range of from 40 degrees to 75 degrees with respect to a radial direction of the ring-shaped member, and are arranged at equal intervals in a circumferential direction of the ring-shaped member, wherein the oil grooves are formed of (i) communicating oil grooves, each having opening portions (42, 44) at an inner peripheral end and an outer peripheral end of the ring-shaped member, respectively, and each being a recessed portion formed continuously to connect the opening portion at the inner peripheral end and the opening portion at the outer peripheral end, and (ii) non-communicating oil grooves, each having an opening portion only at the inner peripheral end of the ring-shaped member having the inner peripheral end and the outer peripheral end, and each being a recessed portion formed continuously to extend from the opening portion at the inner peripheral end to a vicinity of the outer peripheral, wherein a total number of the communicating oil grooves is two or more, wherein the communicating oil grooves and the non-communicating oil grooves are arranged with periodic regularity in the circumferential direction of the ring-shaped member, characterized by a communicating oil groove area ratio expressed by Communicating oil groove area ratio = S1 / S1 + S2 falls within a range of from 0.680 to 0.85, where S1 represents a sum of plane areas (mm 2) of first to n-th communicating oil grooves, S2 represents a sum of plane areas (mm 2) of first to m-th non-communicating oil grooves, "n" represents a total number of the communicating oil grooves, and "m" represents a total number of the non-communicating oil grooves. wherein at least one of the front surface or the back surface of the ring-shaped member slides against another member, wherein at least one of the front surface or the back surface has four or more oil grooves, each being a flow path for lubricating oil, wherein an oil groove carrying surface is a surface to slide against another member, wherein the oil grooves each have a longitudinal direction that forms an angle falling within a range of from 40 degrees to 75 degrees with respect to a radial direction of the ring-shaped member, and are arranged at equal intervals in a circumferential direction of the ring-shaped member, wherein the oil grooves are formed of (i) communicating oil grooves, each having opening portions (42, 44) at an inner peripheral end and an outer peripheral end of the ring-shaped member, respectively, and each being a recessed portion formed continuously to connect the opening portion at the inner peripheral end and the opening portion at the outer peripheral end, and (ii) non-communicating oil grooves, each having an opening portion only at the inner peripheral end of the ring-shaped member having the inner peripheral end and the outer peripheral end, and each being a recessed portion formed continuously to extend from the opening portion at the inner peripheral end to a vicinity of the outer peripheral, wherein a total number of the communicating oil grooves is two or more, wherein the communicating oil grooves and the non-communicating oil grooves are arranged with periodic regularity in the circumferential direction of the ring-shaped member, characterized by a communicating oil groove area ratio expressed by Communicating oil groove area ratio = S1 / S1 + S2 falls within a range of from 0.680 to 0.85, where S1 represents a sum of plane areas (mm 2) of first to n-th communicating oil grooves, S2 represents a sum of plane areas (mm 2) of first to m-th non-communicating oil grooves, "n" represents a total number of the communicating oil grooves, and "m" represents a total number of the non-communicating oil grooves.